FAQ'S

Q: What does an extended warranty cover on a furnace or an air conditioner?

Typically, an extended warranty covers the failure of a part or component of the product due to the malfunction of the unit or one or more of its parts or components. The extended warranty is on the furnace, boiler, or air conditioner and not on accessory components not included as part of the equipment. Examples of accessory components:

Thermostats (not specifically covered)
Condensate pumps
Registers
Humidifiers
Ultraviolet air purifiers
Filters
Air vents (boilers)
Backflow preventers (boilers)
Zone valves (boilers)
Pressure reducing valves (boilers)
Expansion tanks (boilers)
And any item not included in the ‘box’…

Therefore, an extended warranty typically does NOT cover:

Failure caused by lack of electrical power (external fuse or circuit breaker blown, switch turned off, meter failure, etc.) or lack of natural gas (gas line shut-off, a problem with meter, etc.). Why: The unit would have functioned correctly with power or fuel – not the fault of the manufacturer.
Failure caused by lack of maintenance (plugged filters, lack of cleaning, plugged condensate lines, dead batteries, etc.) Why: The manufacturer requires maintenance to be performed on the unit; maintenance related failures are excluded.
Failure caused by exhaust or air intake vent blockage – failure caused by factor outside of manufacturer control.
Failure caused by external component failure: includes all of the accessory components listed above, or failure of the distribution system (i.e. ductwork or piping).
Failures caused by acts of God, natural disasters, abuse and anything acting upon the equipment beyond the control of the manufacturer.
Loss of performance or aesthetics.

Some warranties require proof of equipment maintenance as required by the manufacturer. For more guidance, consult your warranty paperwork.

Q: What should be considered when choosing an appliance service plan?

First, read the fine prints. Many utility companies offer home appliance service plans that provide repair coverage on furnaces, central air conditioners, water heaters, clothes washers and dryers, range/ovens, and many other home appliances. Under these types of plans, the customer pays the company a yearly fee and the company agrees to repair any appliances covered under the plan. In the event of a covered repair, customers are not charged for parts, labor, or a service trip. However, as with any maintenance or service plan, you should read the fine print carefully to make sure you understand the costs, terms, and limitations of these plans.

Costs
Always consider whether the yearly cost is worth the advantage of having coverage in the event of an appliance breakdown. Companies offer a variety of service plans. Costs vary, depending on the type of coverage each plan offers. For example, a basic plan covering only a furnace can cost around $70-85 a year. A deluxe plan covering all major appliances might cost over $220 a year.
Covered Services And Non-Covered Services
Always ask for a complete list of covered services and parts, and what is not covered. Some services and parts you might expect to be covered may not be covered. For example, a furnace tune-up and safety check is not covered under most standard furnace service plans.
Service Employees
Some utility companies use employees other than their own for service calls (contractors). Ask the company if its contractors are licensed, bonded, and carry appropriate insurance. Request a list of the company's approved contractors.
Limitation of Liabilities
Carefully review the terms and conditions of the plan. An appliance service plan limits the company's liability if it is unable to respond to a service call or successfully repair a covered appliance. For example, under most plans, companies will not pay for repairs when the company hasn't responded to a service call promptly due to workload emergencies and weather conditions and the customer has to have someone else repair a broken appliance. Under some plans, if the company's cost to repair an appliance exceeds its current market value, the company will not repair it. Ask for a copy of the terms and conditions of the plan and review it carefully.

Q: What should a maintenance checklist include?

A typical maintenance check-up should include the following.

Check thermostat settings
to ensure the cooling and heating system keeps you comfortable when you are home and saves energy while you are away.
Tighten all electrical connections
and measure voltage and current on motors. Faulty electrical connections can cause unsafe operation of your system and reduce the life of major components.
Lubricate all moving parts.
Parts that lack lubrication cause friction in motors and increases the amount of electricity you use.
Check and inspect the condensate drain
in your central air conditioner, furnace and/or heat pump (when in cooling mode). A plugged drain can cause water damage in the house and affect indoor humidity levels.
Check controls of the system
to ensure proper and safe operation. Check the starting cycle of the equipment to assure the system starts, operates, and shuts off properly.

Cooling Specific

Clean evaporator and condenser air conditioning coils
Dirty coils reduce the system's ability to cool your home and cause the system to run longer, increasing energy costs and reducing the life of the equipment.
Check your central air conditioner's refrigerant level
and adjust if necessary. Too much or too little refrigerant will make your system less efficient increasing energy costs and reducing the life of the equipment.
Clean and adjust blower components to provide proper system airflow for greater comfort levels
Airflow problems can reduce your system's efficiency by up to 15 percent.

Heating Specific

Check all gas (or oil) connections, gas pressure, burner combustion and heat exchanger
Improperly operating gas (or oil) connections are a fire hazard and can contribute to health problems. A dirty burner or cracked heat exchanger causes improper burner operation. Either can cause the equipment to operate less safely and efficiently.

Actions to Do Yourself

Inspect, clean, or change air filters
once a month in your central air conditioner, furnace, and/or heat pump. Your contractor can show you how to do this. A dirty filter can increase energy costs and damage your equipment, leading to early failure.

General Informaton

GI Q1

G1 Q2

GI Q3

Heating and Cooling Systems

1. What are the different types of cooling systems?

2. Ductless: What are the advantages and disadvantages?

3. What are some money and energy saving air conditioning tips?

4. What are the different types of heating systems?

5. When is a good time to replace a heating system?

6. Why do good furnaces go bad?

7. What are things to look for when purchasing a new heating system?

8. What should I do if there is an odor when my furnace starts up?

9. How do heat pumps achieve energy savings and CO2 emissions reduction?

10.What is the best way to operate and maintain a heat pump?

Q: What are the different types of cooling systems?

Central Air Conditioners

Central air conditioners circulate cool air through a system of supply and return ducts. Supply ducts and registers (i.e., openings in the walls, floors, or ceilings covered by grills) carry cooled air from the air conditioner to the home. This cooled air becomes warmer as it circulates through the home; then it flows back to the central air conditioner through return ducts and registers.

Air conditioners help to dehumidify the incoming air, but in extremely humid climates or in cases where the air conditioner is oversized, it may not achieve a low humidity. Running a dehumidifier in your air-conditioned home will increase your energy use, both for the dehumidifier itself and because the air conditioner will require more energy to cool your house. A preferable alternative is a dehumidifying heat pipe, which can be added as a retrofit to most existing systems.

TYPES OF CENTRAL AIR CONDITIONERS

A central air conditioner is either a split-system unit or a packaged unit.

In a split-system central air conditioner, an outdoor metal cabinet contains the condenser and compressor, and an indoor cabinet contains the evaporator. In many split-system air conditioners, this indoor cabinet also contains a furnace or the indoor part of a heat pump. The air conditioner's evaporator coil is installed in the cabinet or main supply duct of this furnace or heat pump. If your home already has a furnace but no air conditioner, a split-system is the most economical central air conditioner to install.

In a packaged central air conditioner, the evaporator, condenser, and compressor are all located in one cabinet, which usually is placed on a roof or on a concrete slab next to the house's foundation. This type of air conditioner also is used in small commercial buildings. Air supply and return ducts come from indoors through the home's exterior wall or roof to connect with the packaged air conditioner, which is usually located outdoors. Packaged air conditioners often include electric heating coils or a natural gas furnace. This combination of air conditioner and central heater eliminates the need for a separate furnace indoors.

CHOOSING OR UPGRADING YOUR CENTRAL AIR CONDITIONER

Central air conditioners are more efficient than room air conditioners. In addition, they are out of the way, quiet, and convenient to operate. To save energy and money, you should try to buy an energy-efficient air conditioner and reduce your central air conditioner's energy use. In an average air-conditioned home, air conditioning consumes more than 2,000 kilowatt-hours of electricity per year, causing power plants to emit about 3,500 pounds of carbon dioxide and 31 pounds of sulfur dioxide.

If you are considering adding central air conditioning to your home, the deciding factor may be the need for ductwork.

If you have an older central air conditioner, you might choose to replace the outdoor compressor with a modern, high-efficiency unit. If you do so, consult a local heating and cooling contractor to assure that the new compressor is properly matched to the indoor unit. However, considering recent changes in refrigerants and air conditioning designs, it might be wiser to replace the entire system.

Today's best air conditioners use 30% to 50% less energy to produce the same amount of cooling as air conditioners made in the mid-1970s. Even if your air conditioner is only 10 years old, you may save 20% to 40% of your cooling energy costs by replacing it with a newer, more efficient model.

Proper sizing and installation are key elements in determining air conditioner efficiency. Too large a unit will not adequately remove humidity. Too small a unit will not be able to attain a comfortable temperature on the hottest days. Improper unit location, lack of insulation, and improper duct installation can greatly diminish efficiency.

When buying an air conditioner, look for a model with a high efficiency. Central air conditioners are rated according to their seasonal energy efficiency ratio (SEER). SEER indicates the relative amount of energy needed to provide a specific cooling output. Many older systems have SEER ratings of 6 or less. The minimum SEER allowed today is 13. Look for the ENERGY STAR® label for central air conditioners with SEER ratings of 13 or greater, but consider using air conditioning equipment with higher SEER ratings for greater savings.

New residential central air conditioner standards went into effect on January 23, 2006. Air conditioners manufactured after January 26, 2006, must achieve a SEER of 13 or higher. SEER 13 is 30% more efficient than the previous minimum SEER of 10. The standard applies only to appliances manufactured after January 23, 2006. Equipment with a rating less than SEER 13 manufactured before this date may still be sold and installed.

The average homeowner will remain unaffected by this standard change for some time to come. The standards do not require you to change your existing central air conditioning units, and replacement parts and services should still be available for your home's systems. The "lifespan" of a central air conditioner is about 15 to 20 years. Manufacturers typically continue to support existing equipment by making replacement parts available and honoring maintenance contracts after the new standard goes into effect.

Other features to look for when buying an air conditioner include:

A thermal expansion valve and a high-temperature rating (EER) greater than 11.6, for high-efficiency operation, when the weather is at its hottest
A variable speed air handler for new ventilation systems
A unit that operates quietly
A fan-only switch, so you can use the unit for nighttime ventilation to substantially reduce air-conditioning costs
A filter check light to remind you to check the filter after a predetermined number of operating hours
An automatic-delay fan switch to turn off the fan a few minutes after the compressor turns off.

INSTALLATION AND LOCATION OF AIR CONDITIONERS

If your air conditioner is installed correctly, or if major installation problems are found and fixed, it will perform efficiently for years with only minor routine maintenance. However, many air conditioners are not installed correctly. As an unfortunate result, modern energy-efficient air conditioners can perform almost as poorly as older inefficient models.

When installing a new central air conditioning system, be sure that your contractor:

Allows adequate indoor space for the installation, maintenance, and repair of the new system, and installs an access door in the furnace or duct to provide a way to clean the evaporator coil
Uses a duct-sizing methodology such as the Air Conditioning Contractors of America (ACCA)Manual D
Ensures there are enough supply registers to deliver cool air and enough return air registers to carry warm house air back to the air conditioner
Installs duct work within the conditioned space, not in the attic, wherever possible
Seals all ducts with duct mastic and heavily insulates attic ducts
Locates the condensing unit where its noise will not keep you or your neighbors awake at night, if possible
Locates the condensing unit where no nearby objects will block airflow to it
Verifies that the newly installed air conditioner has the exact refrigerant charge and airflow rate specified by the manufacturer
Locates the thermostat away from heat sources, such as windows or supply registers.

If you are replacing an older or failed split system, be sure that the evaporator coil is replaced with a new one that exactly matches the condenser coil in the new condensing unit. (The air conditioner's efficiency will likely not improve if the existing evaporator coil is left in place; in fact, the old coil could cause the new compressor to fail prematurely.)

Ductless Mini-Split Air Conditioners

Ductless, mini split-system air-conditioners (mini splits) have numerous potential applications in residential, commercial, and institutional buildings. The most common applications are in multifamily housing or as retrofit add-ons to houses with "non-ducted" heating systems, such as hydronic (hot water heat), radiant panels, and space heaters (wood, kerosene, propane). They can also be a good choice for room additions and small apartments, where extending or installing distribution ductwork (for a central air-conditioner or heating systems) is not feasible.

Like central systems, mini splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit, which houses the power cable, refrigerant tubing, suction tubing, and a condensate drain, links the outdoor and indoor units.

ADVANTAGES

The main advantages of mini splits are their small size and flexibility for zoning or heating and cooling individual rooms. Many models can have as many as four indoor air handling units (for four zones or rooms) connected to one outdoor unit. The number depends on how much heating or cooling is required for the building or each zone (which in turn is affected by how well the building is insulated). Each of the zones will have its own thermostat, so you only need to condition that space when it is occupied, saving energy and money.

Ductless mini-split systems are also often easier to install than other types of space conditioning systems. For example, the hook-up between the outdoor and indoor units generally requires only a three-inch (~8 centimeter [cm]) hole through a wall for the conduit. Also, most manufacturers of this type of system can provide a variety of lengths of connecting conduits. So, if necessary, you can locate the outdoor unit as far away as 50 feet (~15 meters [m]) from the indoor evaporator. This makes it possible to cool rooms on the front side of a building house with the compressor in a more advantageous or inconspicuous place on the outside of the building.

Since mini splits have no ducts, they avoid the energy losses associated with ductwork of central forced air systems. Duct losses can account for more than 30% of energy consumption for space conditioning, especially if the ducts are in an unconditioned space such as an attic.

Compared with other add-on systems, mini splits offer more flexibility in interior design options. The indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available. Most indoor units have profiles of about seven inches (~18 cm) deep and usually come with sleek, high-tech-looking jackets. Many also offer a remote control to make it easier to turn the system on and off when it's positioned high on a wall or suspended from a ceiling. Split-systems can also help to keep your home safer, because there is only a small hole in the wall. Through-the-wall and window mounted room air-conditioners can provide an easy entrance for intruders.

DISADVANTAGES

The primary disadvantage of mini splits is their cost. Such systems cost about $1,500 to $2,000 per ton (12,000 Btu per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost twice as much as window units of similar capacity.

The installer must also correctly size each indoor unit and judge the best location for its installation. Oversized or incorrectly located air-handlers often result in short-cycling, which wastes energy and does not provide proper temperature or humidity control. Too large a system is also more expensive to buy and operate.

Some people may not like the appearance of the indoor part of the system. While less obtrusive than a window room air conditioner, they seldom have the built-in look of a central system. There must also be a place to drain condensate water near the outdoor unit.

Qualified installers and service people for mini splits may not be easy to find. In addition, most conventional heating and cooling contractors have large investments in tools and training for sheet metal duct systems. They need to use (and charge for) these to earn a return on their investment, so they may not recommend ductless systems except where a ducted system would be difficult for them to install.

ROOM AIR CONDITIONERS

Room or window air conditioners cool rooms rather than the entire home or business. If they provide cooling only where they're needed, room air conditioners are less expensive to operate than central units, even though their efficiency is generally lower than that of central air conditioners.

Smaller room air conditioners (i.e., those drawing less than 7.5 amps of electricity) can be plugged into any 15- or 20-amp, 115-volt household circuit that is not shared with any other major appliances. Larger room air conditioners (i.e., those drawing more than 7.5 amps) need their own dedicated 115-volt circuit. The largest models require a dedicated 230-volt circuit.

Q: Ductless: What are the advantages and disadvantages?

Ductless, mini-split-system heat pumps (mini splits) make good retrofit add-ons to houses with "non-ducted" heating systems, such as hydronic (hot water heat), radiant panels, and space heaters (wood, kerosene, propane). They can also be a good choice for room additions, where extending or installing distribution ductwork is not feasible.

Like standard air-source heat pumps, mini splits have two main components: an outdoor compressor/condenser, and an indoor air-handling unit. A conduit, which houses the power cable, refrigerant tubing, suction tubing, and a condensate drain, links the outdoor and indoor units.

Advantages

The main advantages of mini splits are their small size and flexibility for zoning or heating and cooling individual rooms. Many models can have as many as four indoor air handling units (for four zones or rooms) connected to one outdoor unit. The number depends on how much heating or cooling is required for the building or each zone (which in turn is affected by how well the building is insulated). Since each of the zones will have its own thermostat, you only need to condition that place when someone is there. This will save energy and money.

Ductless mini-split systems are also often easier to install than other types of space conditioning systems. For example, the hook-up between the outdoor and indoor units generally requires only a three-inch hole through a wall for the conduit. Also, most manufacturers of this type of system can provide a variety of lengths of connecting conduits. If necessary, you can locate the outdoor unit as far away as 50 feet from the indoor evaporator. This makes it possible to cool rooms on the front side of a building house with the compressor in a more advantageous or inconspicuous place on the outside of the building.

In comparison to other add-on systems, mini splits offer more flexibility in interior design options. The indoor air handlers can be suspended from a ceiling, mounted flush into a drop ceiling, or hung on a wall. Floor-standing models are also available. Most indoor units have profiles of about seven inches deep and usually come with sleek, high tech-looking jackets. Many also offer a remote control to make it easier to turn the system on and off when it's positioned high on a wall or suspended from a ceiling.

Split-systems can also help to keep your home safer since there is only a small hole in the wall. Through-the-wall and window mounted room air-conditioners can provide an easy entrance for intruders.

Disadvantages

The primary disadvantage of mini splits is their cost. Such systems cost about $1,500–$2,000 per ton (12,000 Btu per hour) of cooling capacity. This is about 30% more than central systems (not including ductwork) and may cost twice as much as window units of similar capacity.

Q: What are some money and energy saving air conditioning tips?

Whole house fans help cool your home by pulling cool air through the house and exhausting warm air through the attic. They are effective when operated at night and when the outside air temperature is cooler than the inside.
Set your thermostat at 78ºF or higher. Each degree setting below 78ºF will increase energy consumption by approximately 8%. Be careful, however, that if you're A/C is oversized the diminished run-time from raising the thermostat setting may result in too-high indoor humidity in some locations.
Don't set your thermostat at a colder temperature setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and, therefore, unnecessary expense.
Set the fan speed on high except in very humid weather. When it's humid set the fan speed on low. You'll get better cooling.
Consider ceiling fans to spread the cooled air more effectively through your home without greatly increasing your power use.
Don't place lamps or TV sets near your air conditioning thermostat.
Plant trees or shrubs to shade air-conditioning units but not to block the airflow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.
Use bath and kitchen fans sparingly when the air conditioner is operating to avoid pulling warm, moist air into your home.
Inspect and clean both the indoor and outdoor coils. The indoor coil in your air conditioner acts as a magnet for dust because it is constantly wetted during the cooling season. Dirt build-up on the indoor coil is the single most common cause of poor efficiency. The outdoor coil must also be checked periodically for dirt build-up and cleaned if necessary.
Check the refrigerant charge. The circulating fluid in your air conditioner is a special refrigerant gas that is put in when the system is installed. If the system is overcharged or undercharged with refrigerant, it will not work properly. You will need a service contractor to check the fluid and adjust it appropriately.
Shade east and west windows.
When possible, delay heat-generating activities, such as cooking and dishwashing, until evening on hot days.
Keep the house closed tight during the day. Don't let in unwanted heat and humidity. Ventilate at night either naturally or with fans.

Q: What are the different types of heating systems?

A variety of technologies are available for heating your house. In addition to heat pumps, which are discussed separately, many homes use the following approaches:

-Furnaces and Boilers: By far the most common way to heat a home.

-Wood and Pellet-Fuel Heating: Provides a way to heat your home using biomass or waste sources.

-Electric Resistance Heating: Among the most expensive ways to heat a home.

-Active Solar Heating: Uses the sun to heat either air or liquid and can serve as a supplemental heat source.

-Radiant Heating: Can draw on a number of energy sources, including electricity, boilers, solar energy, and wood and pellet-fuel heating.

-Small Space Heaters: Less efficient than central heating systems, but can save energy when used appropriately. While forced-air heating systems rely on the same type of ducts used by heat pumps and air conditioners, water and steam heat systems use radiators that only deliver heat.

Q: When is a good time to replace a heating system?

Certain telltale signs indicate it's time to consider replacing heating and cooling equipment, or improving the performance of your overall system. It may be time to call a professional contractor to help you make a change if:

1. Your heat pump or air conditioner is more than 10 years old.

Consider replacing with ENERGY STAR qualified equipment that uses 20 percent less energy than new standard models.

2. Your furnace or boiler is more than 15 years old.

Consider replacing with an ENERGY STAR qualified furnace, which is 15% more efficient than a conventional furnace. If you have a boiler, consider replacing with ENERGY STAR qualified boiler that is 10% more efficient than a new, standard model.

3. Your equipment needs frequent repairs and your energy bills are going up.

Your cooling or heating equipment may have become less efficient.

4. Some rooms in your home are too hot or too cold.

Improper equipment operation, duct problems or inadequate insulation could be the cause.

5. No one is home for long periods of the day and you do not have a programmable thermostat.

Install an ENERGY STAR qualified programmable thermostat or have a good contractor install one and instruct you on its use — to start saving energy and money while they're away or sleeping.

6. Your home has humidity problems.

Poor equipment operation, inadequate equipment, and leaky ductwork can cause the air to be too dry in the winter or too humid in the summer.

7. Your home has excessive dust.

Leaky ducts can pull particles and air from attics, crawl spaces and basements and distribute them throughout your house. Sealing your ducts may be a solution.

8. Your heating or cooling system is noisy.

You could have an undersized duct system or a problem with the indoor coil of your cooling equipment.

Q: Why do good furnaces go bad?

Statistics show, two out of every 10 furnaces over 15 years old, where annual maintenance has been inadequate or ignored, will likely have a breached and potentially dangerous heat exchanger. The problem won't present itself in an easily detectible manner. Instead, as fractures in a heat exchanger worsen, increased amounts of carbon monoxide (a poisonous bi-product of furnace combustion) can find its way into your home instead of being vented outdoors. And, the odds of this occurring increase as your equipment ages.

The age of your furnace may be irrelevant

It is important to know that every furnace, no matter the age, can become unsafe. Newer government energy guidelines have mandated furnace manufacturers to increase fuel efficiency. One obvious way they've done this is to reduce the thickness of metal used in their heat exchangers to allow faster transfer of heat from the burning fuel to the indoor air.

The downside of thinner metal being used in today's heat exchangers is that, if the furnace is not sized correctly or installed properly, many of the newer furnaces have been found to fail within just a few years. Unfortunately, homeowners don't know if this has occurred until a problem is detected. For this reason, the qualifications and reputation of the installing contractor should be a determining factor when taking bids instead of price alone.

What causes a heat exchanger to fail?

The heat exchanger is the metal passage separating combustion products and gasses from the indoor air being heated. This metal is exposed to the hot flame within the furnace and is constantly expanding and contracting as the furnace heats up and cools down. The stress of this constant expansion and contraction will eventually wear the metal out. This is known as "metal fatigue". Over time, this will cause the metal in the heat exchanger to split or crack-no different than if you were to bend a paper clip back and forth until it breaks.

Horizontal furnaces (typically installed in crawlspaces below the home) and oversized furnaces (where the gas is continually turning on and off) are subject to more stress and usually wear out sooner due to their operating conditions. These types of furnaces should be inspected yearly-especially if more than ten years old.

Keeping your furnace's blower clean is critical

Dirt build-up on the blades of your furnace's blower can also contribute to early aging of your furnace's heat exchanger. Blower cleaning is critical since a build-up of dirt on the blower blades will reduce the furnace's airflow and cause it to use more electricity. The lower airflow will cause the furnace to run hotter, increasing the rate of expansion and contraction of the heat exchanger's metal. The end result is excessive metal fatigue and eventual premature failure.

How can I know if my furnace is safe?

A professional inspection is the most accurate way to know for sure if your furnace's heat exchanger is sound. Electronic "gas sniffers" can help find bad heat exchangers, but it is important that they never be used as the reason to condemn a furnace. They can be fooled and are wrong in a great many circumstances.

Many companies offer an inspection service for around $60. However, these include very little, if any, actual cleaning of the furnace, and typically take only about 20 to 30 minutes. This type of program may provide a feeling of confidence in your equipment, but they don't make your furnace run any better.

A better investment is a complete tune-up and cleaning that includes a heat exchanger inspection. When comparing prices, it is important to know that a good tune-up should take a technician anywhere from 1 to 2 hours, and will always include the removal and cleaning of the furnace blower.

If ever your heat exchanger is found to be faulty, knowing how to verify the problem may save you from unnecessary expense and grief. Unfortunately, without this knowledge, trusting homeowners can sometimes be misled by unscrupulous companies into replacing their entire furnace.

See the problem for yourself

The only true way to know for sure if your heat exchanger is cracked is to actually see the crack. If a service technician claims to be able to see a crack in your heat exchanger, he should be able to show it to you, too. Most reputable companies will insist on this.

You can also verify it for yourself. This can be done by removing the furnace's blower, or by cutting an access into the ductwork on top of the furnace, and then inserting a light into the burner area where the flame usually is. If the heat exchanger is cracked, you will see light inside the ductwork shining through the crack. Another way is to spray water on the outside of the heat exchanger. If there is a crack, you will see the water seeping through it, causing the area inside the exchanger to show a wet spot. For either test, a mirror can help you look into the different burner sections. If you still have doubts, we'll be happy to give you a second opinion.

What are my options?

If you do have a failed heat exchanger, it is serious and, if left uncorrected, can be fatal. That is why, when a failed heat exchanger is discovered, the furnace must be shut off for obvious safety reasons. Since it is against the law to repair it, the heat exchanger or the entire furnace must be replaced.

Which should you choose?

First, refer to any warranty information you have relating to your furnace. However, if the failure was due to improper sizing or installation, consider that a new heat exchanger will be subject to the same conditions which led to the premature failure of the original. Under these circumstances, a new furnace may be a wiser investment. Of course, other factors such as the age and efficiency of your existing furnace should also be considered in making your decision.

Q: What are things to look for when purchasing a new heating system?

The first thing you need to know before you begin the search for a new heating system is whether you are currently using the best fuel source available. For example, if you currently use propane gas, you may look to switch to natural gas if it has become available in your area. There are pros and cons to every fuel, and a switch could add hundreds of dollars to the cost of a new heating system, but be well worth it in the long run.

It usually pays to check with your heating contractor who can help you get a feel for what you will save in your energy costs over the next five to ten years with the fuel source you choose. By doing this, your contractor can show you what your long term savings will be vs. your short term investment. You may also be eligible for rebates and/or special financing options with approved credit.

If a contractor simply looks at your old system and quotes you a price on a system of the same size, be skeptical.

One size does not fit all. No matter which type of heating system you decide upon, you must install a system that is properly sized for your house. This is usually something that the homeowner cannot do on his or her own. Your heating contractor should perform an approved heat loss on your home to determine exactly how much heat is required to heat your home comfortably on the coldest day of the year, and no more. Installing too large of a heating system will only waste energy and break down more often, shortening the life of the system.

If your contractor simply looks at your old system and quotes you a price on a system of the same size, be skeptical.

This is a common practice and it is irresponsible. Your old heating system is probably between 15 and 40 years old. Now, take a moment and think of all the changes your home has undergone in that time...new doors, new windows, added insulation in the attic, perhaps even an addition to the home. All of these factor into the proper sizing of your heating system.

Even if your home has gone through no major changes since the installation of the existing heating system, who's to say that it was ever properly sized to begin with? It simply cannot be stressed enough: a heating system must fit the home exactly. A system that is too big or too small will lead to future problems, higher fuel bills and the premature failure of the system.

AFUE and efficiency. Today's heating systems come in two basic efficiencies, the 80% efficient models and the 90% efficient models. Efficiencies are measured by their Annual Fuel Utilization of Energy, or AFUE. What does this mean? It is very similar to the way Miles Per Gallon or MPG, is used to determine how efficient a car's engine is. The higher the rating, the more efficient the heating system.

High efficiency or low efficiency? The minimum efficient heating system you can purchase today is 78% and the maximum is about 97%. You may be saying to yourself, "It seems silly not to purchase the most efficient heating system available since it will save me the most money on my energy bills."

A system that is too big or too small will lead to future problems, higher fuel bills and the premature failure of the system.

This may be true, but there are many other factors involved when you are considering a very high-efficiency system. These include whether you will vent the system, using a direct vent or the chimney. The 90% efficient systems require what is called direct venting. This method bypasses your chimney and goes directly through the wall of the house. There are very strict codes set by both the manufacturers and most states as to how direct venting may be done. If these specifications are not rigidly followed, the results could lead to carbon monoxide poisoning.

The 80% efficient systems are vented using your existing chimney, and thus are much more economical to install. In some instances, it is mandatory to line your existing chimney with an aluminum or steel liner to ensure that no condensation of the waste gasses occurs within the chimney causing masonry problems down the road.

If your existing furnace or boiler is over 17 years old, upgrading to an 80% efficient system will probably come close to cutting your existing fuel bill by a third.

The best advice for selecting a new heating system is to compare the total investment in an 80% efficient system versus that of a 90% efficient system, factor out any incentives, rebates, etc., and break it all down to an apples-to-apples comparison. Then have the contractor show you what your energy savings will be. At this point, your choice should be obvious.

Q: What should I do if there is an odor when my furnace starts up?

If your home or office furnace gives off an acrid or pungent odor when it first starts up, it may indicate a potential health risk. This odor is caused by airborne dust and household chemicals that have settled on the furnace. These are “burnt” off as the furnace heats up. The main source of this problem is from unclean, or poorly filtered ductwork where dust, pet hair and debris have settled and decayed over the years.

Since most homeowners don't see the filth that the air you breathe passes through when your furnace runs, the old adage applies, “out of sight — out of mind!” Unfortunately, the neglected ductwork still bears a cost...mainly your health.

The difference between a good job and a poor one is simply time, effort and commitment. A good job will typically take a good part of the day to perform. The best way to tell if it has been done right is if the company cleaning it has no problem helping you spot check it when they're done. In fact, because we take the needed time to do the job right, our company will offer to show you any part of your system when we're done. We even have infra-red cameras to make it easy to see what your ducts look like before and after the job is done. Without this assurance, you may be setting yourself up to get less than a quality job. Why would you want to pay someone who isn't willing to help you ensure that you got what you paid for?

When arranging to have your ducts cleaned, you'll find wisdom in the old adages: “Seeing is believing!”, “You get what you pay for”, and “A job worth doing is worth doing right.”

Q: How do heat pumps achieve energy savings and CO2 emissions reduction?

Heat pumps and energy saving:

This section gives a brief introduction to heat pumps. Based on six basic facts about heat supply the value of heat pumps is discussed. It is argued that heat pumps are very energy efficient, and therefore environmentally benign.

An efficient technology:
Heat pumps offer the most energy-efficient way to provide heating and cooling in many applications, as they can use renewable heat sources in our surroundings. Even at temperatures we consider to be cold, air, ground, and water contain useful heat that's continuously replenished by the sun. By applying a little more energy, a heat pump can raise the temperature of this heat energy to the level needed. Similarly, heat pumps can also use waste heat sources, such as from industrial processes, cooling equipment or ventilation air extracted from buildings. A typical electrical heat pump will just need 100 kWh of power to turn 200 kWh of freely available environmental or waste heat into 300 kWh of useful heat.

Six basic facts about heating:
Through this unique ability, heat pumps can radically improve the energy efficiency and environmental value of any heating system that is driven by primary energy resources such as fuel or power. The following six facts should be considered when any heat supply system is designed:

direct combustion to generate heat is never the most efficient use of fuel;
heat pumps are more efficient because they use renewable energy in the form of low-temperature heat;
if the fuel used by conventional boilers were redirected to supply power for electric heat pumps, about 35-50% less fuel would be needed, resulting in 35-50% less emissions;
around 50% savings are made when electric heat pumps are driven by CHP (combined heat and power or cogeneration) systems;
whether fossil fuels, nuclear energy, or renewable power is used to generate electricity, electric heat pumps make far better use of these resources than do resistance heaters;
the fuel consumption, and consequently the emissions rate, of an absorption or gas-engine heat pump is about 35-50% less than that of a conventional boiler.

A large and worldwide potential:
If it is further considered that heat pumps can meet space heating, hot water heating, and cooling needs in all types of buildings, as well as many industrial heating requirements, it is clear that heat pumps have a large and worldwide potential.

Of the global CO2 emissions that amounted to 22 billion tonnes in 1997, heating in building causes 30% and industrial activities cause 35%. The potential CO2 emissions reduction with heat pumps is calculated as follows:

6.6 billion tonnes CO2 comes from heating buildings (30% of total emissions).
1.0 billion tonnes can be saved by residential and commercial heat pumps, assuming that they can provide 30% of the heating for buildings, with an emission reduction of 50%.

The total CO2 reduction potential of 1.2 billion tonnes is about 6% of the global emissions! This is one of the largest that a single technology can offer, and this technology is already available in the marketplace. And with higher efficiencies in power plants as well as for the heat pump itself, the future global emissions saving potential is even 16%.

In some regions of the world, heat pumps already play an important role in energy systems. But if this technology is to achieve more widespread use, a decisive effort is needed to stimulate heat pump markets and to further optimize the technology. It is encouraging that a number of governments and utilities are strongly supporting heat pumps. In all cases, it is important to ensure that both heat pump applications and policies are based on a careful assessment of the facts, drawn from as wide an experience base as possible. The IEA Heat Pump Centre sees it as one of its key roles to ensure that these facts are available to a wide audience, including policymakers, utilities, market parties, and heat pump users.

Q: What is the best way to operate and maintain a heat pump?

Proper operation of your heat pump will save energy. Do not set back the heat pump's thermostat if it causes the backup heating to come on; backup heating systems are usually more expensive to operate. Continuous indoor fan operation can degrade heat pump performance unless a high-efficiency, variable-speed fan motor is used. Operate the system on the "auto" fan setting on the thermostat.

Like all heating and cooling systems, proper maintenance is key to efficient operation. The difference between the energy consumption of a well-maintained heat pump and a severely neglected one ranges from 10%–25%.

Clean or change filters once a month or as needed, and maintain the system according to manufacturer's instructions. Dirty filters, coils, and fans reduce airflow through the system. Reduced airflow decreases system performance and can damage your system's compressor. Clean outdoor coils whenever they appear dirty; occasionally, turn off power to the fan and clean it; remove vegetation and clutter from around the outdoor unit. Clean the supply and return registers within your home, and straighten their fins if bent.

You should also have a professional technician service your heat pump at least every year. The technician can do the following:

Inspect ducts, filters, blower, and indoor coil for dirt and other obstructions
Diagnose and seal duct leakage
Verify adequate airflow by measurement
Verify correct refrigerant charge by measurement
Check for refrigerant leaks
Inspect electric terminals, and if necessary, clean and tighten connections, and apply nonconductive coating
Lubricate motors, and inspect belts for tightness and wear
Verify correct electric control, making sure that heating is locked out when the thermostat calls for cooling and vice versa
Verify correct thermostat operation.

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Indoor Air Quality

Q: What should I know about biological pollutants in my home?

Outdoor air pollution in cities is a major health problem. Much effort and money continues to be spent cleaning up pollution in the outdoor air. But air pollution can be a problem where you least expect it, in the place you may have thought was safest -- your home. Many ordinary activities such as cooking, heating, cooling, cleaning, and redecorating can cause the release and spread of indoor pollutants at home. Studies have shown that the air in our homes can be even more polluted than outdoor air.

Many Americans spend up to 90 percent of their time indoors, often at home. Therefore, breathing clean indoor air can have an important impact on health. People who are inside a great deal may be at greater risk of developing health problems or having problems made worse by indoor air pollutants. These people include infants, young children the elderly and those with chronic illnesses.

What are Biological Pollutants?

Biological pollutants are or were living organisms. They promote poor indoor air quality and may be a major cause of days lost from work or school, and of doctor and hospital visits. Some can even damage surfaces inside and outside your house. Biological pollutants can travel through the air and are often invisible.

Some common indoor biological pollutants are:

Animal Dander (minute scales from hair, feathers, or skin)
Dust Mite and Cockroach parts
Infectious agents (bacteria or viruses)
Pollen

Some of these substances are in every home. It is impossible to get rid of them all. Even a spotless home may permit the growth of biological pollutants. Two conditions are essential to support biological growth nutrients and moisture. These conditions can be found in many locations, such as bathrooms, damp or flooded basements, wet appliances (such as humidifiers or air conditioners), and even some carpets and furniture.

Modern materials and construction techniques may reduce the amount of outside air brought into buildings which may result in high moisture levels inside. Using humidifiers, unvented heaters, and air conditioners in our homes has increased the chances of moisture forming on interior surfaces. This encourages the growth of certain biological pollutants.

The Scope of the Problem:

Most information about sources and health effects of biological pollutants is based on studies of large office buildings and two surveys of homes in northern U.S. and Canada. These surveys show that 30% to 50% of all structures have damp conditions which may encourage the growth and buildup of biological pollutants. This percentage is likely to be higher in warm, moist climates.

Some diseases or illnesses have been linked with biological pollutants in the indoor environment. However, many of them also have causes unrelated to the indoor environment. Therefore, we do not know how many health problems relate only to poor indoor air.

Health Effects of Biological Pollutants

All of us are exposed to biological pollutants. However, the effects on our health depend upon the type and amount of biological pollution and the individual person. Some people do not experience health reactions from certain biological pollutants, while others may experience one or more of the following reactions:

Allergic
Infectious
Toxic

Except for the spread of infections indoors, ALLERGIC REACTIONS may be the most common health problem with indoor air quality in homes. They are often connected with animal dander (mostly from cats and dogs), with house dust mites (microscopic animals living in household dust), and with pollen. Allergic reactions can range from mildly uncomfortable to life-threatening, as in a severe asthma attack.

Some common signs and symptoms are:

Watery eyes
Runny nose and sneezing
Nasal congestion
Itching
Coughing
Wheezing and difficulty breathing
Headache
Fatigue

Health experts are especially concerned about people with asthma These people have very sensitive airways that can react to various irritants, making breathing difficult. The number of people who have asthma has greatly increased in recent years. The number of people with asthma has gone up by 59 percent since 1970, to a total of 9.6 million people. Asthma in children under 15 years of age has increased 41 percent in the same period, to a total of 2.6 million children. The number of deaths from asthma is up by 68 percent since 1979, to a total of almost 4,400 deaths per year.

Talking to Your Doctor:

Are you concerned about the effects on your health that may be related to biological pollutants in your home? Before you discuss your concerns with your doctor, you should know the answers to the following questions. This information can help the doctor determine whether your health problems may be related to biological pollution.

Does anyone in the family have frequent headaches, fevers, itchy watery eyes, a stuffy nose, dry throat, or a cough? Does anyone complain of feeling tired or dizzy all the time? Is anyone wheezing or having difficulties breathing on a regular basis?
Did these symptoms appear after you moved to a new or different home?
Do the symptoms disappear when you go to school or the office or go away on a trip, and return when you come back?
Have you recently remodeled your home or done any energy conservation work, such as installing insulation, storm windows, or weather stripping? Did your symptoms occur during or after these activities?
Does your home feel humid? Can you see moisture on the windows or on other surfaces, such as walls and ceilings?
What is the usual temperature in your home? Is it very hot or cold?
Have you recently had water damage?
Is your basement wet or damp?
Is there any obvious mold or mildew?
Does any part of your home have a musty or moldy odor?
Is the air stale?
Do you have pets?
Do your house plants show signs of mold?
Do you have air conditioners or humidifiers that have not been properly cleaned?
Does your home have cockroaches or rodents?

INFECTIOUS DISEASES caused by bacteria and viruses, such as flu, measles, chickenpox, and tuberculosis, may be spread indoors. Most infectious diseases pass from person to person through physical contact. Crowded conditions with poor air circulation can promote this spread. Some bacteria and viruses thrive in buildings and circulate through indoor ventilation systems. For example, the bacterium causing Legionnaire's disease, a serious and sometimes lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some large buildings.

TOXIC REACTIONS are the least studied and understood health problem caused by some biological air pollutants in the home. Toxins can damage a variety of organs and tissues in the body, including the liver, the central nervous system, the digestive tract, and the immune system.

Checking Your Home:

There is no simple and cheap way to sample the air in your home to determine the level of all biological pollutants. Experts suggest that sampling for biological pollutants is not a useful problem-solving tool. Even if you had your home tested, it is almost impossible to know which biological pollutant(s) cause various symptoms or health problems. The amount of most biological substances required to cause disease is unknown and varies from one person to the next.

Does this make the problem sound hopeless? On the contrary, you can take several simple, practical actions to help remove sources of biological pollutants, to help get rid of pollutants, and to prevent their return.

Self-Inspection: A Walk Through Your Home:

Begin by touring your household. Follow your nose, and use your eyes. Two major factors help create conditions for biological pollutants to grow nutrients and constant moisture with poor air circulation.

Dust and construction materials, such as wood, wallboard, and insulation, contain nutrients that allow biological pollutants to grow. Firewood also is a source of moisture, fungi, and bugs.

Appliances such as humidifiers, kerosene and gas heaters, and gas stoves add moisture to the air.

A musty odor, moisture on hard surfaces, or even water stains, may be caused by:

Air-conditioning units
Basements, attics, and crawlspaces
Bathrooms
Carpets
Heating and air-conditioning ducts
Humidifiers and dehumidifiers
Refrigerator drip pans

What You Can Do about Biological Pollutants:

Before you give away the family pet or move, there are less drastic steps that can be taken to reduce potential problems. Properly cleaning and maintaining your home can help reduce the problem and may avoid interrupting your normal routine. People who have health problems such as asthma, or are allergic, may need to do this and more. Discuss this with your doctor.

Moisture Control

Water in your home can come from many sources. Water can enter your home by leaking or by seeping through basement floors. Showers or even cooking can add moisture to the air in your home. The amount of moisture that the air in your home can hold depends on the temperature of the air. As the temperature goes down, the air is able to hold less moisture. This is why, in cold weather, moisture condenses on cold surfaces (for example, drops of water form on the inside of a window). This moisture can encourage biological pollutants to grow.

There are many ways to control moisture in your home:

Fix leaks and seepage. If water is entering the house from the outside, your options range from simple landscaping to extensive excavation and waterproofing. (The ground should slope away from the house). Water in the basement can result from the lack of gutters or a water flow toward the house. Water leaks in pipes or around tubs and sinks can provide a place for biological pollutants to grow.
Put a plastic cover over dirt crawlspaces to prevent moisture from coming in from the ground. Be sure crawlspaces are well-ventilated.
Use exhaust fans in bathrooms and kitchens to remove moisture to the outside (not into the attic) Vent your clothes dryer to the outside.
Turn off certain appliances (such as humidifiers or kerosene heaters) if you notice moisture on windows and other surfaces.
Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants.
Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows. (A storm window installed on the inside works better than one installed on the outside ) Open doors between rooms (especially doors to closets which may be colder than the rooms) to increase circulation. Circulation carries heat to the cold surfaces Increase air circulation by using fans and by moving furniture from wall corners to promote air and heat circulation. Be sure that your house has a source of fresh air and can expel excessive moisture from the home.
Pay special attention to carpet on concrete floors. Carpet can absorb moisture and serve as a place for biological pollutants to grow. Use area rugs which can be taken up and washed often In certain climates, if carpet is to be installed over a concrete floor, it may be necessary to use a vapor barrier (plastic sheeting) over the concrete and cover that with sub-flooring (insulation covered with plywood) to prevent a moisture problem.
Moisture problems and their solutions differ from one climate to another. The Northeast is cold and wet, the Southwest is hot and dry, the South is hot and wet, and the Western Mountain states are cold and dry. All of these regions can have moisture problems. For example, evaporative coolers used in the Southwest can encourage the growth of biological pollutants. In other hot regions, the use of air conditioners that cool the air too quickly may prevent the air conditioners from running long enough to remove excess moisture from the air. The types of construction and weatherization for the different climates can lead to different problems and solutions.

Where Biological Pollutants may be Found in the Home

Dirty air conditioners
Dirty humidifiers and/or dehumidifiers
Bathroom without vents or windows
Kitchen without vents or windows
Dirty refrigerator drip pans
Laundry room with unvented dryer
Unventilated attic
Carpet on damp basement floor
Bedding
Closet on outside wall
Dirty heating/air conditioning system
Dogs or cats
Water damage (around windows, the roof or the basement)

Maintain and Clean all Appliances that Come in Contact with Water

Have major appliances, such as furnaces, heat pumps, and central air conditioners, inspected and cleaned regularly by a professional, especially before seasonal use. Change filters on heating and cooling systems according to the manufacturer's directions. (In general, change filters monthly during use.) When first turning on the heating or air conditioning at the start of the season, consider leaving your home until it airs out.
Have window or wall air-conditioning units cleaned and serviced regularly by a professional, especially before the cooling season. Air conditioners can help reduce the entry of allergy-causing pollen. But they may also become a source of biological pollutants if not properly maintained. Clean the coils and rinse the drain pans according to the manufacturer's instructions, so water can-not collect in pools.
Have furnace-attached humidifiers cleaned and serviced regularly by a professional, especially before the heating season.
Follow manufacturer's instructions when using any type of humidifier Experts differ on the benefits of using humidifiers. If you do use a portable humidifier (approximately 1 to 2 gallon tanks), be sure to empty its tank every day and refill with distilled or demineralized water, or even fresh tap water if the other types of water are unavailable For larger portable humidifiers, change the water as recommended by the manufacturer. Unplug the appliance before cleaning. Every third day, clean all surfaces coming in contact with water with a 3% solution of hydrogen peroxide, using a brush to loosen deposits Some manufacturers recommend using diluted household bleach for cleaning and maintenance, generally in a solution of one-half cup bleach to one gallon water When any household chemical, rinse well to remove all traces of chemical before refilling humidifier.
Empty dehumidifiers daily and clean often. If possible, have the appliance drip directly into a drain. Follow the manufacturer's instructions for cleaning and maintenance. Always disconnect the appliance before cleaning.
Clean refrigerator drip pans regularly according to the manufacturer's instructions. If refrigerator and freezer doors don't seal properly, moisture may build up and mold can grow. Remove any mold on door gaskets and replace faulty gaskets.

Clean Surfaces

Clean moist surfaces, such as showers and kitchen counters.
Remove mold from walls, ceilings, floors, and paneling. Do not simply cover mold with paint, stain, varnish, or a moisture-proof sealer, as it may resurface.
Replace moldy shower curtains, or remove them and scrub well with a household cleaner and rinse before rehanging them.

Dust Control:

Controlling dust is very important for people who are allergic to animal dander and mites. You cannot see mites, but you can either remove their favorite breeding grounds or keep these areas dry and clean. Dust mites can thrive in sofas, stuffed chairs, carpets, and bedding. Open shelves, fabric wallpaper, knickknacks, and venetian blinds are also sources of dust mites. Dust mites live deep in the carpet and are not removed by vacuuming. Many doctors suggest that their mite-allergic patients use washable area rugs rather than wall-to-wall carpet.

Always wash bedding in hot water (at least 130° F) to kill dust mites. Cold water won't do the job. Launder bedding at least every 7 to 10 days.
Use synthetic or foam rubber mattress pads and pillows, and plastic mattress covers if you are allergic Do not use fuzzy wool blankets, feather or wool-stuffed comforters, and feather pillows.
Clean rooms and closets well, dust and vacuum often to remove surface dust. Vacuuming and other cleaning may not remove all animal dander, dust mite material, and other biological pollutants. Some particles are so small they can pass through vacuum bags and remain in the air If you are allergic to dust, wear a mask when vacuuming or dusting. People who are highly allergy-prone should not perform these tasks. They may even need to leave the house when someone else is cleaning.

Before You Move:

Protect yourself by inspecting your potential new home. If you identify problems, have the landlord or seller correct them before you move in, or even consider moving elsewhere.

Have professionals check the heating and cooling system, including humidifiers and vents. Have duct lining and insulation checked for growth.
Check for exhaust fans in bathrooms and kitchens If there are no vents, do the kitchen and bathrooms have at least one window a piece? Does the cooktop have a hood vented outside? Does the clothes dryer vent outside? Are all vents to the outside of the building, not in attics or crawlspaces?
Look for obvious mold growth throughout the house, including attics, basements, and crawlspaces and around the foundation. See if there are many plants close to the house, particularly if they are damp and rotting. They are a potential source of biological pollutants. Downspouts from roof gutters should route water away from the building.
Look for stains on the walls, floor or carpet (including any carpet over concrete floors) as evidence of previous flooding or moisture problems. Is there moisture on windows and surfaces? Are there signs of leaks or seepage in the basement?
Look for rotted building materials which may suggest moisture or water damage.
If you or anyone else in the family has a pet allergy, ask if any pets have lived in the home.
Examine the design of the building. Remember that in cold climates, overhanging areas, rooms over unheated garages, and closets on outside walls may be prone to problems with biological pollutants.
Look for signs of cockroaches.

Warning!

Carefully read instructions for use and any cautionary labeling on cleaning products before beginning cleaning procedures.

Do not mix any chemical products. Especially, never mix cleaners containing bleach with any product (such as ammonia) which does not have instructions for such mixing. When chemicals are combined, a dangerous gas can sometimes be formed.
Household chemicals may cause burning or irritation to skin and eyes.
Household chemicals may be harmful if swallowed or inhaled.
Avoid contact with skin, eyes, mucous membranes, and clothing.
Avoid breathing vapor. Open all windows and doors and use an exhaust fan that sends the air outside.
Keep household chemicals out of reach of children.
Rinse treated surface areas well to remove all traces of chemicals.
Correcting Water Damage

What if damage is already done? Follow these guidelines for correcting water damage:

Throw out mattresses, wicker furniture, straw baskets and the like that have been water damaged or contain mold. These cannot be recovered.
Discard any water-damaged furnishings such as carpets, drapes, stuffed toys, upholstered furniture, and ceiling tales, unless they can be recovered by steam cleaning or hot water washing and thorough drying.
Remove and replace wet insulation to prevent conditions where biological pollutants can grow.

Q: How can I control indoor air pollution?

The three most common approaches to reducing indoor air pollution, in order of effectiveness, are:

Source Control: Eliminate or control the sources of pollution;
Ventilation: Dilute and exhaust pollutants through outdoor air ventilation, and
Air Cleaning: Remove pollutants through proven air cleaning methods.

Of the three, the first approach -- source control -- is the most effective. This involves minimizing the use of products and materials that cause indoor pollution, employing good hygiene practices to minimize biological contaminants (including the control of humidity and moisture, and occasional cleaning and disinfection of wet or moist surfaces), and using good housekeeping practices to control particles.

The second approach -- outdoor air ventilation -- is also effective and commonly employed. Ventilation methods include installing an exhaust fan close to the source of contaminants, increasing outdoor air flows in mechanical ventilation systems, and opening windows, especially when pollutant sources are in use.

The third approach -- air cleaning -- is not generally regarded as sufficient in itself, but is sometimes used to supplement source control and ventilation. Air filters, electronic particle air cleaners, and ionizers are often used to remove airborne particles, and gas adsorbing material is sometimes used to remove gaseous contaminants when source control and ventilation are inadequate.

Q: What is a guide to indoor air quality?

Identifying Air Quality Problems:

Some health effects can be useful indicators of an indoor air quality problem, especially if they appear after a person moves to a new residence, remodels or refurnishes a home, or treats a home with pesticides. If you think that you have symptoms that may be related to your home environment, discuss them with your doctor or your local health department to see if they could be caused by indoor air pollution. You may also want to consult a board-certified allergist or an occupational medicine specialist for answers to your questions.

Another way to judge whether your home has or could develop indoor air problems is to identify potential sources of indoor air pollution. Although the presence of such sources does not necessarily mean that you have an indoor air quality problem, being aware of the type and number of potential sources is an important step toward assessing the air quality in your home.

A third way to decide whether your home may have poor indoor air quality is to look at your lifestyle and activities. Human activities can be significant sources of indoor air pollution. Finally, look for signs of problems with the ventilation in your home. Signs that can indicate your home may not have enough ventilation include moisture condensation on windows or walls, smelly or stuffy air, dirty central heating and air cooling equipment, and areas where books, shoes, or other items become moldy. To detect odors in your home, step outside for a few minutes, and then upon reentering your home, note whether odors are noticeable.

Measuring Pollutant Levels:

The federal government recommends that you measure the level of radon in your home. Without measurements there is no way to tell whether radon is present because it is a colorless, odorless, radioactive gas. Inexpensive devices are available for measuring radon. EPA provides guidance as to risks associated with different levels of exposure and when the public should consider corrective action. There are specific mitigation techniques that have proven effective in reducing levels of radon in the home. (See "Radon" for additional information about testing and controlling radon in homes.)

For pollutants other than radon, measurements are most appropriate when there are either health symptoms or signs of poor ventilation and specific sources or pollutants have been identified as possible causes of indoor air quality problems. Testing for many pollutants can be expensive. Before monitoring your home for pollutants besides radon, consult your state or local health department or professionals who have experience in solving indoor air quality problems in nonindustrial buildings.

Weatherizing Your Home:

The federal government recommends that homes be weatherized in order to reduce the amount of energy needed for heating and cooling. While weatherization is underway, however, steps should also be taken to minimize pollution from sources inside the home. (See "Improving the Air Quality in Your Home" for recommended actions.) In addition, residents should be alert to the emergence of signs of inadequate ventilation, such as stuffy air, moisture condensation on cold surfaces, or mold and mildew growth. Additional weatherization measures should not be undertaken until these problems have been corrected.

Weatherization generally does not cause indoor air problems by adding new pollutants to the air. (There are a few exceptions, such as caulking, that can sometimes emit pollutants.) However, measures such as installing storm windows, weather stripping, caulking, and blown-in wall insulation can reduce the amount of outdoor air infiltrating into a home. Consequently, after weatherization, concentrations of indoor air pollutants from sources inside the home can increase.

Three Basic Strategies

1. Source Control

Usually the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions. Some sources, like those that contain asbestos, can be sealed or enclosed; others, like gas stoves, can be adjusted to decrease the amount of emissions. In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs. Specific sources of indoor air pollution in your home are listed later in this section.

2. Ventilation Improvements

Another approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors. Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room where the fan is located and also increase the outdoor air ventilation rate.

It is particularly important to take as many of these steps as possible while you are involved in short-term activities that can generate high levels of pollutants--for example, painting, paint stripping, heating with kerosene heaters, cooking, or engaging in maintenance and hobby activities such as welding, soldering, or sanding. You might also choose to do some of these activities outdoors, if you can and if weather permits.

Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home. Some of these designs include energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers). For more information about air-to-air heat exchangers, contact the Conservation and Renewable Energy Inquiry and Referral Service (CAREIRS), PO Box 3048, Merrifield, VA 22116; (800) 523-2929.

3. Air Cleaners

There are many types and sizes of air cleaners on the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. Some air cleaners are highly effective at particle removal, while others, including most table-top models, are much less so. Air cleaners are generally not designed to remove gaseous pollutants.

The effectiveness of an air cleaner depends on how well it collects pollutants from indoor air (expressed as a percentage efficiency rate) and how much air it draws through the cleaning or filtering element (expressed in cubic feet per minute). A very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but a less efficient collector. The long-term performance of any air cleaner depends on maintaining it according to the manufacturer's directions.

Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source. Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources. People with a sensitivity to particular sources may find that air cleaners are helpful only in conjunction with concerted efforts to remove the source.

Over the past few years, there has been some publicity suggesting that houseplants have been shown to reduce levels of some chemicals in laboratory experiments. There is currently no evidence, however, that a reasonable number of houseplants remove significant quantities of pollutants in homes and offices. Indoor houseplants should not be over-watered because overly damp soil may promote the growth of microorganisms which can affect allergic individuals.

At present, EPA does not recommend using air cleaners to reduce levels of radon and its decay products. The effectiveness of these devices is uncertain because they only partially remove the radon decay products and do not diminish the amount of radon entering the home. EPA plans to do additional research on whether air cleaners are, or could become, a reliable means of reducing the health risk from radon. EPA's booklet, Residential Air-Cleaning Devices, provides further information on air-cleaning devices to reduce indoor air pollutants.

For most indoor air quality problems in the home, source control is the most effective solution. This section takes a source-by-source look at the most common indoor air pollutants, their potential health effects, and ways to reduce levels in the home. (For a summary of the points made in this section, see the section entitled "Reference Guide to Major Indoor Air Pollutants in the Home.") EPA has recently released, Ozone Generators That Are Sold As Air Cleaners. The purpose of this document (which is only available via this web site) is to provide accurate information regarding the use of ozone-generating devices in indoor occupied spaces. This information is based on the most credible scientific evidence currently available.

EPA has recently published, "Should You Have the Air Ducts in Your Home Cleaned?" EPA-402-K-97-002, October 1997. This document is intended to help consumers answer this often confusing question. The document explains what air duct cleaning is, provides guidance to help consumers decide whether to have the service performed in their home, and provides helpful information for choosing a duct cleaner, determining if duct cleaning was done properly, and how to prevent contamination of air ducts.

To order a printed copy of this booklet, send your publication request to: publications@cpsc.gov

System Support & Accessories

Q: What should I know about insulation?

You can reduce your home's heating and cooling costs through proper insulation techniques. These techniques will also make your home more comfortable.

Any air sealing efforts will complement your insulation efforts, and vice versa. Proper moisture control and ventilation strategies will improve the effectiveness of air sealing and insulation, and vice versa.

Therefore, a home's energy efficiency depends on a balance between all of these elements:

Air sealing
Insulation
Moisture control
Ventilation

*A proper balance between all of these elements will also result in a more comfortable, healthier home environment.

How Insulation Works:

You need insulation in your home to provide resistance to heat flow. The more heat flow resistance your insulation provides, the lower your heating and cooling costs.

Heat flows naturally from a warmer to a cooler space. In the winter, this heat flow moves directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors-wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house. To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.

An insulation's resistance to heat flow is measured or rated in terms of its thermal resistance or R-value.

Adding Insulation to an Existing Home:

Unless your home was specially constructed for energy efficiency, you can usually reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but adding insulation to a newer home may also pay for itself within a few years.

To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where.

A qualified home energy auditor will include an insulation check as a routine part of a whole-house energy audit. An energy audit will also help identify areas of your home that are in need of air sealing. (Before you insulate, you should make sure that your home is properly air sealed.)

If you don't want an energy audit, you need to find out the following:

Where your home is, isn't, and/or should be insulated
What type of insulation you have
The R-value and the thickness or depth (inches) of the insulation you have

If you live in a newer house, you can probably find out this information from the builder. If you live in an older house, you'll need to inspect the insulation yourself if you don't want an energy audit.

Inspecting and Evaluating Your Insulation:

Check the attic, walls, and floors adjacent to an unheated space, like a garage or basement. The structural elements are usually exposed in these areas, which makes it easy to see what type of insulation you have and to measure its depth or thickness (inches).
Inspect the exterior walls using an electrical outlet:
1. Turn off the power to the outlet.
2. Remove the outlet cover and shine a flashlight into the crack around the outlet box. You should be able to see if there is insulation in the wall and possibly how thick it is.
3. Pull out a small amount of insulation if needed to help determine the type of insulation.
4. Check outlets on the first and upper floors, if any, and in old and new parts of a house. Just because you find insulation in one wall doesn't mean that it's everywhere in the house.
Inspect and measure the thickness (inches) of any insulation in unfinished basement ceilings and walls, or above crawl spaces. If the crawl space isn't ventilated, it may have insulation in the perimeter wall. If your house is relatively new, it may have been built with insulation outside the basement or foundation walls. If so, the insulation in these spaces won't be visible. The builder or the original homeowner might be able to tell you if exterior insulation was used.
Once you've determined the type of insulation you have in these areas and its thickness (inches), see the U.S. Department of Energy's online Insulation Fact Sheet for how to determine the R-values of insulation previously installed in your home.

The R-Value of Insulation:

An R-value indicates an insulation's resistance to heat flow. The higher the R-value, the greater the insulating effectiveness.

The R-value depends on the type of insulation and includes its material, thickness, and density. When calculating the R-value of a multi-layered installation, add the R-values of the individual layers. Installing more insulation in your home increases the R-value and the resistance to heat flow.

The effectiveness of an insulation's resistance to heat flow also depends on how and where the insulation is installed. For example, insulation that is compressed will not provide its full rated R-value. The overall R-value of a wall or ceiling will be somewhat different from the R-value of the insulation itself because some heat flows around the insulation through the studs and joists. Therefore, it's important to properly install your insulation to achieve the maximum R-value.

The amount of insulation or R-value you'll need depends on your climate, type of heating and cooling system, and the section of the house you plan to insulate.

Determining Recommended R-Values:

When you find out the R-values of your insulation either from an energy audit, the home builder, or your own inspection, you can then use the U.S. Department of Energy's Zip-Code Insulation Program to determine how much insulation you should add and where to achieve the recommended insulation levels for maximum energy efficiency.

Types of Insulation:

When insulating your home, you can choose from many types of insulation. To choose the best type of insulation, you should first determine the following:

Where you want or need to install/add insulation
The recommended R-values for areas you want to insulate.

Q: How does insulation work?

Insulation in your home provides resistance to heat flow. The more heat flow resistance your insulation provides, the lower your heating and cooling costs. Properly insulating your home not only reduces heating and cooling costs, but also improves comfort.

To understand how insulation works it helps to understand heat flow, which involves three basic mechanisms -- conduction, convection, and radiation. Conduction is the way heat moves through materials, such as when a spoon placed in a hot cup of coffee conducts heat through its handle to your hand. Convection is the way heat circulates through liquids and gases, and is why lighter, warmer air rises, and cooler, denser air sinks in your home. Radiant heat travels in a straight line and heats anything solid in its path that absorbs its energy.

Most common insulation materials work by slowing conductive heat flow and -- to a lesser extent -- convective heat flow. Radiant barriers and reflective insulation systems work by reducing radiant heat gain. To be effective, the reflective surface must face an air space.

Regardless of the mechanism, heat flows from warmer to cooler until there is no longer a temperature difference. In your home, this means that in winter, heat flows directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors. Heat flow can also move indirectly through interior ceilings, walls, and floors -- wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house.

To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.

Q: What are blower door tests & how do they work?

Blower door tests:

Professional energy auditors use blower door tests to help determine a home's airtightness. Our Energy Saver 101 infographic explains the importance of a blower door test during a home energy audit.

These are some reasons for establishing the proper building tightness:

Reducing energy consumption due to air leakage
Avoiding moisture condensation problems
Avoiding uncomfortable drafts caused by cold air leaking in from the outdoors
Determining how much mechanical ventilation might be needed to provide acceptable indoor air quality.

How they work:

A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. The auditors may use a smoke pencil to detect air leaks. These tests determine the air infiltration rate of a building.

Blower doors consist of a frame and flexible panel that fit in a doorway, a variable-speed fan, a pressure gauge to measure the pressure differences inside and outside the home, and an airflow manometer and hoses for measuring airflow.

Preparing for a blower door test:

Take the following steps to prepare your home for a blower door Test:

If you heat with wood, be sure all fires are completely out - not even coals - before the auditor arrives. Remove any ashes from open fireplaces.
Plan to do a walk-through of your home with the auditor. Be prepared to point out areas that you know are drafty or difficult to condition comfortably.
Expect the auditor to request access to all areas of your home including closets, built-in cabinets, attics, crawl spaces, and any unused rooms.
The auditor will need to close all exterior doors and windows, open all interior doors, and close any fireplace dampers, doors, and woodstove air inlets.
Expect the auditor to set controls on all atmospheric fossil fuel appliances to ensure that they do not fire during the test. The auditor should return them to the original position after the test.
Expect the test to take up to an hour or more, depending on the complexity of your home.

Q: What are ventilation strategies?

There are three basic ventilation strategies—natural ventilation, spot ventilation, and whole-house ventilation.

Natural Ventilation:

Natural ventilation is the uncontrolled air movement in and out of the cracks and small holes in a home. In the past, this air leakage usually diluted air pollutants enough to maintain adequate indoor air quality. Today, we are sealing those cracks and holes to make our homes more energy-efficient, and after a home is properly air sealed, ventilation is necessary to maintain a healthy and comfortable indoor environment. Opening windows and doors also provides natural ventilation, but many people keep their homes closed up because they use central heating and cooling systems year-round. Natural ventilation is unpredictable and uncontrollable—you can't rely on it to ventilate a house uniformly. Natural ventilation depends on a home's airtightness, outdoor temperatures, wind, and other factors. During mild weather, some homes may lack sufficient natural ventilation for pollutant removal. During windy or extreme weather, a home that hasn’t been air sealed properly will be drafty, uncomfortable, and expensive to heat and cool.

Spot Ventilation:

Spot ventilation can improve the effectiveness of natural and whole-house ventilation by removing indoor air pollution and/or moisture at its source. Spot ventilation includes the use of localized exhaust fans, such as those used above kitchen ranges and in bathrooms. ASHRAE recommends intermittent or continuous ventilation rates for bathrooms of 50 or 20 cubic feet per minute and kitchens of 100 or 25 cubic feet per minute, respectively.

Whole-House Ventilation:

The decision to use whole-house ventilation is typically motivated by concerns that natural ventilation won't provide adequate air quality, even with source control by spot ventilation. Whole-house ventilation systems provide controlled, uniform ventilation throughout a house. These systems use one or more fans and duct systems to exhaust stale air and/or supply fresh air to the house.

There are four types of systems:

Exhaust ventilation systems work by depressurizing the building and are relatively simple and inexpensive to install.
Supply ventilation systems work by pressurizing the building and are also relatively simple and inexpensive to install.
Balanced ventilation systems, if properly designed and installed, neither pressurize nor depressurize a house. Rather, they introduce and exhaust approximately equal quantities of fresh outside air and polluted inside air.
Energy recovery ventilation systems provide controlled ventilation while minimizing energy loss. They reduce the costs of heating ventilated air in the winter by transferring heat from the warm inside air being exhausted to the fresh (but cold) supply air. In the summer, the inside air cools the warmer supply air to reduce ventilation cooling costs.

Avoiding Heat Buildup:

Keeping the outside heat outside, avoiding heat-generating activities, and using spot ventilation can help keep your home cool during hot days.

To avoid heat buildup in your home, plan ahead by landscaping your lot to shade your house. If you replace your roof, use a light-colored material to help it reflect heat. Insulate your house to at least the recommended levels to help keep out the heat, and consider using a radiant barrier.

On hot days, whenever outdoor temperatures are higher than the temperature inside your house, close tightly all the windows and exterior doors. Also, install window shades or other window treatments and close the shades. Shades will help block out not only direct sunlight, but also radiated heat from the outdoors, and insulated shades will reduce the conduction of heat into your home through your windows.

Cooking can be a major source of heat within a home. On hot days, avoid using the oven; cook on the stovetop, or better yet, use only a microwave oven. For stovetop or oven cooking, use the spot ventilation of your oven hood to help remove the heat from the house (this will suck some hot outside air into your home, so don't overdo it). Outdoor grilling is a great way to avoid cooking indoors, and of course, going out to eat or ordering take-out work as well.

Bathing, washing laundry, and other activities can also pump heat into your home. When you shower or take a bath, use the spot ventilation of a bathroom fan to remove the heat and humidity from your home. Your laundry room might also benefit from spot ventilation. If you use an electric dryer, be sure it's vented to the outside (for safety, gas dryers should ALWAYS be vented to the outside). If you live in an older home with a sump that your laundry drains to, drain the sump after running any loads in hot water (or better yet, avoid using hot water for your laundry).

Finally, avoid any activities that generate a lot of heat, such as running a computer, burning open flames, running a dishwasher, and using hot devices such as curling irons or hair dryers. Even stereos and televisions will add some heat to your home.

Q: How does air sealing work?

Air Sealing:

Reducing the amount of air that leaks in and out of your home is a cost-effective way to cut heating and cooling costs, improve durability, increase comfort, and create a healthier indoor environment. Caulking and weatherstripping are two simple and effective air-sealing techniques that offer quick returns on investment, often one year or less. Caulk is generally used for cracks and openings between stationary house components such as around door and window frames, and weatherstripping is used to seal components that move, such as doors and operable windows.

Air Leakage:

Air leakage occurs when outside air enters and conditioned air leaves your house uncontrollably through cracks and openings. It is unwise to rely on air leakage for ventilation. During cold or windy weather, too much air may enter the house. When it's warmer and less windy, not enough air may enter, which can result in poor indoor air quality. Air leakage also contributes to moisture problems that can affect occupants’ health and the structure’s durability. An added benefit is that sealing cracks and openings reduces drafts and cold spots, improving comfort.

The recommended strategy is to reduce air leakage as much as possible and to provide controlled ventilation as needed. Before air sealing, you should first:

Detect air leaks:

For a thorough and accurate measurement of air leakage in your home, hire a qualified technician to conduct an energy assessment, particularly a blower door test. A blower door test, which depressurizes a home, can reveal the location of many leaks. A complete energy assessment will also help determine areas in your home that need more insulation.

Without a blower door test, there are ways to find some air leaks yourself.

On the outside of your house, inspect all areas where two different building materials meet, including:

All exterior corners
Outdoor water faucets
Where siding and chimneys meet
Areas where the foundation and the bottom of exterior brick or siding meet.

Inside your home, inspect around the following areas for any cracks and gaps that could cause air leaks:

Electrical outlets
Switch plates
Door and window frames
Electrical and gas service entrances
Baseboards
Weather stripping around doors
Fireplace dampers
Attic hatches
Wall- or window-mounted air conditioners.
Cable TV and phone lines
Where dryer vents pass through walls
Vents and fans.

You can then apply air sealing techniques and materials, including caulk and weatherstripping. If you're planning an extensive remodel of your home that will include some construction, review some of the techniques used for air sealing in new home construction and consider a home energy audit to identify all the ways your home wastes energy and money.

Note that air sealing alone doesn’t eliminate the need for proper insulation to reduce heat flow through the building envelope.

Q: What is moisture control & why is it important?

Properly controlling moisture in your home will improve the effectiveness of your air sealing and insulation efforts, and vice versa. Thus, moisture control contributes to a home's overall energy efficiency.

The best strategy for controlling moisture in your home depends on your climate and how your home is constructed. Before deciding on a moisture control strategy for your home, you may first want to understand:

How Moisture Moves through a Home:

To help understand the principles of moisture control, you need to understand the basics of how moisture can move through your home.

Moisture or water vapor moves in and out of a home in three ways:

With air currents
By diffusion through materials
By heat transfer

Of these three, air movement accounts for more than 98% of all water vapor movement in building cavities. Air naturally moves from a high pressure area to a lower one by the easiest path possible-generally through any available hole or crack in the building envelope. Moisture transfer by air currents is very fast (in the range of several hundred cubic feet of air per minute). Thus, you need to carefully and permanently air seal any unintended paths to control air movement.

The other two driving forces-diffusion through materials and heat transfer-are much slower processes. Most common building materials slow moisture diffusion to a large degree, although they never stop it completely. Insulation also helps reduce heat transfer or flow.

The laws of physics govern how moist air reacts within various temperature conditions. The study of moist air properties is technically referred to as "psychrometrics." A psychrometric chart is used by professionals to determine at what temperature and moisture concentration water vapor begins to condense. This is called the "dew point." By understanding how to find the dew point, you will better understand how to avoid moisture problems in your house.

Relative humidity (RH) refers to the amount of moisture contained in a quantity of air compared to the maximum amount of moisture the air could hold at the same temperature. As air warms, its ability to hold water vapor increases; this capacity decreases as air cools. For example, according to the psychometric chart, air at 68°F (20°C) with 0.216 ounces of water (H2O) per pound of air (14.8g H2O/kg air) has a 100% RH. The same air at 59°F (15°C) reaches 100% RH with only 0.156 ounces of water per pound of air (10.7g H2O/kg air). The colder air holds about 28% of the moisture that the warmer air does. The moisture that the air can no longer hold condenses on the first cold surface it encounters (the dew point.) If this surface is within an exterior wall cavity, wet insulation and framing will be the result.

In addition to air movement, you also can control temperature and moisture content. Since insulation reduces heat transfer or flow, it also moderates the effect of temperature across the building envelope cavity. In most U.S. climates, properly installed vapor diffusion retarders can be used to reduce the amount of moisture transfer. Except in deliberately ventilated spaces, such as attics, insulation, and vapor diffusion retarders work together to reduce the opportunity for condensation in a house's ceilings, walls, and floors.

To effectively control moisture in your home, you need to first consider your climate when exploring your moisture control options.

Moisture control strategies typically include the following areas of a home:

Attics
Foundation (includes: Basement, Crawl space, Slab-on-grade floors)
Walls

In most U.S. climates, you can use vapor diffusion retarders in these areas of your home to control moisture. Proper ventilation should also be part of a moisture control strategy.

Vapor Barriers or Vapor Diffusion Retarders:

In most U.S. climates, vapor barriers or vapor diffusion retarders should be considered as part of a moisture control strategy for a home.

How They Work:

A vapor barrier or vapor diffusion retarder (VDR) is a material that reduces the rate at which water vapor can move through a material. The older term "vapor barrier" is still used even though it may inaccurately imply that the material stops all of the moisture transfer. Since everything allows some water vapor to diffuse through it to some degree, the term "vapor diffusion retarder" is more accurate.

The ability of a material to retard the diffusion of water vapor is measured by units known as "perms" or permeability. A perm at 73.4°F (23°C) is a measure of the number of grains of water vapor passing through a square foot of material per hour at a differential vapor pressure equal to one inch of mercury (1" W.C.) Any material with a perm rating of less than 1.0 is considered a vapor retarder.

Vapor diffusion retarders can help control moisture in these areas:

Basements
Ceilings
Crawl spaces
Floors
Slab-on-grade foundations
Walls

Effective moisture control in these areas and throughout a home includes air sealing gaps in the structure, not just the use of a vapor diffusion retarder.

How, where, and whether a vapor diffusion retarder should be used depends on the climate. Typically, the number of Heating Degree Days in an area is used to help make these determinations. A Heating Degree Day is a unit that measures how often outdoor daily dry-bulb temperatures fall below an assumed base, normally 65°F (18°C).

Energy Efficiency

Related Health and Safety Issues

Q: How do you read the Energy Guide label?

The ENERGY STAR® Label:

When you shop for a new appliance, look for the ENERGY STAR® label. ENERGY STAR products usually exceed minimum federal standards by a substantial amount.

The ENERGY STAR logo is on all qualified products that meet specific standards for energy efficiency. ENERGY STAR-qualified products exceed the federal minimum standards for efficiency and quality -- sometimes significantly. Look for the label on appliances, electronics, water heaters, windows, and other products that consume energy in your home.

The ENERGYGUIDE Label:

To help you figure out whether an appliance is energy efficient, the federal government requires most appliances to display the bright yellow and black EnergyGuide label. Although these labels will not show you which appliance is the most efficient on the market, they will show you the annual energy consumption and operating cost for each appliance so you can compare them yourself.

How to Read the ENERGYGUIDE Label:

The EnergyGuide label is required to be placed on all appliances by the manufacturers. The label provides information about energy consumption, and shows you how much energy an appliance uses compared with similar models. Keep in mind that the numbers are averages: actual costs will differ somewhat depending on how you use them. The label shows the following:

Maker, model number, and size of the appliance.
Estimated yearly operating cost (based on the national average cost of electricity), and the range of operating costs for similar models.
The ENERGY STAR® logo indicates that this model meets strict criteria for energy efficiency.
Estimated yearly electricity consumption.
Key features of the appliance and the similar models that make up the cost comparison range.

Q: What is important to know about carbon monoxide?

What is carbon monoxide (CO) and how is it produced?

Carbon monoxide (CO) is a deadly, colorless, odorless, poisonous gas. It is produced by the incomplete burning of various fuels, including coal, wood, charcoal, oil, kerosene, propane, and natural gas. Products and equipment powered by internal combustion engine-powered equipment such as portable generators, cars, lawnmowers, and power washers also produce CO.

How many people are unintentionally poisoned by CO?

On average, about 170 people in the United States die every year from CO produced by non-automotive consumer products. These products include malfunctioning fuel-burning appliances such as furnaces, ranges, water heaters and room heaters; engine-powered equipment such as portable generators; fireplaces; and charcoal that is burned in homes and other enclosed areas. In 2005 alone, CPSC staff is aware of at least 94 generator-related CO poisoning deaths. Forty-seven of these deaths were known to have occurred during power outages due to severe weather, including Hurricane Katrina. Still others die from CO produced by non-consumer products, such as cars left running in attached garages. The Centers for Disease Control and Prevention estimates that several thousand people go to hospital emergency rooms every year to be treated for CO poisoning.

What are the symptoms of CO poisoning?

Because CO is odorless, colorless, and otherwise undetectable to the human senses, people may not know that they are being exposed. The initial symptoms of low to moderate CO poisoning are similar to the flu (but without the fever). They include:

Headache
Fatigue
Shortness of breath
Nausea
Dizziness

High-level CO poisoning results in progressively more severe symptoms, including:

Mental confusion
Vomiting
Loss of muscular coordination
Loss of consciousness
Ultimately death

Symptom severity is related to both the CO level and the duration of exposure. For slowly developing residential CO problems, occupants and/or physicians can mistake mild to moderate CO poisoning symptoms for the flu, which sometimes results in tragic deaths. For rapidly developing, high-level CO exposures (e.g., associated with the use of generators in residential spaces), victims can rapidly become mentally confused, and can lose muscle control without having first experienced milder symptoms; they will likely die if not rescued.

How can I prevent CO poisoning?

Make sure appliances are installed and operated according to the manufacturer's instructions and local building codes. Most appliances should be installed by qualified professionals. Have the heating system professionally inspected and serviced annually to ensure proper operation. The inspector should also check chimneys and flues for blockages, corrosion, partial and complete disconnections, and loose connections.
Never service fuel-burning appliances without proper knowledge, skill, and tools. Always refer to the owner's manual when performing minor adjustments or servicing fuel-burning equipment.
Never operate a portable generator or any other gasoline engine-powered tool either in or near an enclosed space such as a garage, house, or other building. Even with open doors and windows, these spaces can trap CO and allow it to quickly build to lethal levels.
Install a CO alarm that meets the requirements of the current UL 2034 or CSA 6.19 safety standards. A CO alarm can provide some added protection, but it is no substitute for proper use and upkeep of appliances that can produce CO. Install a CO alarm in the hallway near every separate sleeping area of the home. Make sure the alarm cannot be covered up by furniture or draperies.
Never use portable fuel-burning camping equipment inside a home, garage, vehicle or tent unless it is specifically designed for use in an enclosed space and provides instructions for safe use in an enclosed area.
Never burn charcoal inside a home, garage, vehicle, or tent.
Never leave a car running in an attached garage, even with the garage door open.
Never use gas appliances such as ranges, ovens, or clothes dryers to heat your home.
Never operate unvented fuel-burning appliances in any room where people are sleeping.
Do not cover the bottom of natural gas or propane ovens with aluminum foil. Doing so blocks the combustion airflow through the appliance and can produce CO.
During home renovations, ensure that appliance vents and chimneys are not blocked by tarps or debris. Make sure appliances are in proper working order when renovations are complete.

What CO level is dangerous to my health?

The health effects of CO depend on the CO concentration and length of exposure, as well as each individual's health condition. CO concentration is measured in parts per million (ppm). Most people will not experience any symptoms from prolonged exposure to CO levels of approximately 1 to 70 ppm but some heart patients might experience an increase in chest pain. As CO levels increase and remain above 70 ppm, symptoms become more noticeable and can include headache, fatigue, and nausea. At sustained CO concentrations above 150 to 200 ppm, disorientation, unconsciousness, and death are possible.

What should I do if I am experiencing symptoms of CO poisoning and do not have a CO alarm, or my CO alarm is not going off?

If you think you are experiencing any of the symptoms of CO poisoning, get outside to fresh air immediately. Leave the home and call your fire department to report your symptoms from a neighbor’s home. You could lose consciousness and die if you stay in the home. It is also important to contact a doctor immediately for a proper diagnosis. Tell your doctor that you suspect CO poisoning is causing your problems. Prompt medical attention is important if you are experiencing any symptoms of CO poisoning. If the doctor confirms CO poisoning, make sure a qualified service person checks the appliances for proper operation before reusing them.

Are CO alarms reliable?

CO alarms always have been and still are designed to alarm before potentially life-threatening levels of CO are reached. The safety standards for CO alarms have been continually improved and currently marketed CO alarms are not as susceptible to nuisance alarms as earlier models.

How should a consumer test a CO alarm to make sure it is working?

Consumers should follow the manufacturer's instructions. Using a test button tests whether the circuitry is operating correctly, not the accuracy of the sensor. Alarms have a recommended replacement age, which can be obtained from the product literature or from the manufacturer.

How should I install a CO Alarm?

CO alarms should be installed according to the manufacturer's instructions. CPSC recommends that one CO alarm be installed in the hallway outside the bedrooms in each separate sleeping area of the home. CO alarms may be installed into a plug-in receptacle or high on the wall. Hard wired or plug-in CO alarms should have battery backup. Avoid locations that are near heating vents or that can be covered by furniture or draperies. CPSC does not recommend installing CO alarms in kitchens or above fuel-burning appliances.

What should you do when the CO alarm sounds?

Never ignore an alarming CO alarm! It is warning you of a potentially deadly hazard.

If the alarm signal sounds do not try to find the source of the CO:

Immediately move outside to fresh air.
Call your emergency services, fire department, or 911.
After calling 911, do a headcount to check that all persons are accounted for. DO NOT reenter the premises until the emergency services responders have given you permission. You could lose consciousness and die if you go in the home.
If the source of the CO is determined to be a malfunctioning appliance, DO NOT operate that appliance until it has been properly serviced by trained personnel.

If authorities allow you to return to your home, and your alarm reactivates within a 24 hour period, repeat steps 1, 2 and 3 and call a qualified appliance technician to investigate for sources of CO from all fuel-burning equipment and appliances, and inspect for proper operation of this equipment. If problems are identified during this inspection, have the equipment serviced immediately. Note any combustion equipment not inspected by the technician and consult the manufacturers’ instructions, or contact the manufacturers directly, for more information about CO safety and this equipment. Make sure that motor vehicles are not, and have not been, operating in an attached garage or adjacent to the residence.

What is the role of the U.S. Consumer Product Safety Commission (CPSC) in preventing CO poisoning?

CPSC staff worked closely with Underwriters Laboratories (UL) to help develop the safety standard (UL 2034) for CO alarms. CPSC helps promote carbon monoxide safety by raising awareness of CO hazards and the need for correct use and regular maintenance of fuel-burning appliances. CPSC staff also works with stakeholders to develop voluntary and mandatory standards for fuel-burning appliances and conducts independent research into CO alarm performance under likely home-use conditions.

Do some cities require that CO alarms be installed?

Many states and local jurisdictions now require CO alarms to be installed in residences. Check with your local building code official to find out about the requirements in your location.

Should CO alarms be used in motor homes and other recreational vehicles?

CO alarms are available for boats and recreational vehicles and should be used. The Recreation Vehicle Industry Association requires CO alarms in motor homes and in towable recreational vehicles that have a generator or are prepped for a generator.

Q: What is important to know about mold?

Potential health effects and symptoms associated with mold exposures include allergic reactions, asthma, and other respiratory complaints.
There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.
If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture.
Fix the source of the water problem or leak to prevent mold growth.
Reduce indoor humidity (to 30-60% ) to decrease mold growth by venting bathrooms, dryers, and other moisture-generating sources to the outside; using air conditioners and de-humidifiers; increasing ventilation; and using exhaust fans whenever cooking, dishwashing, and cleaning.
Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth.
Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles, that are moldy, may need to be replaced.
Prevent condensation: Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof, or floors) by adding insulation.
In areas where there is a perpetual moisture problem, do not install carpeting (i.e., by drinking fountains, by classroom sinks, or on concrete floors with leaks or frequent condensation).
Molds can be found almost anywhere; they can grow on virtually any substance, providing moisture is present. There are molds that can grow on wood, paper, carpet, and foods.