• Tips for Hiring a HVAC Contractor

    10 Tips for Hiring a Heating and Cooling Contractor

    • Study up — Find out about license and insurance requirements for contractors in your state. And before you call a contractor, know the model of your current system and its maintenance history. Also make note of any uncomfortable rooms. This will help potential contractors better understand your heating needs.
    • Ask for referrals — Ask friends, neighbors, and co-workers for contractor referrals. You can also contact local trade organizations for names of members in your area.
    • Call references — Ask contractors for customer references and call them. Ask about the contractor’s installation or service performance, and if the job was completed on time and within budget.
    • Find special offers — A heating and cooling system is one of the largest purchases you’ll make as a homeowner. Keep your costs down by checking around for available rebates on energy-efficient ENERGY STAR qualified heating and cooling equipment.
    • Look for ENERGY STAR — ENERGY STAR qualified products meet strict energy efficiency guidelines set by the U.S. Environmental Protection Agency and offer significant long-term energy savings. Contractors should be able to show you calculations of savings for ENERGY STAR heating and cooling equipment.
    • Expect a home evaluation — The contractor should spend significant time inspecting your current system and home to assess your needs. A bigger system isn’t always better; a contractor should size the heating and cooling system based on the size of your house, level of insulation, and windows. A good contractor will inspect your duct system (if applicable) for air leaks and insulation and measure airflow to make sure it meets manufacturers specifications.
    • Get written, itemized estimates — When comparing contractors’ proposals (bids), be sure to compare cost, energy efficiency and warranties. A lowest price may not be the best deal if it’s not the most efficient because your energy costs will be higher.
    • Get it in ink — Sign a written proposal with a contractor before work gets started. It’ll protect you by specifying project costs, model numbers, job schedule and warranty information.
    • Pass it on — Tell friends and family about ENERGY STAR. Almost one-quarter of households knowingly purchased at least one qualified product last year, and 71% of those consumers say they would recommend ENERGY STAR to a friend. Spread the word, and we can all make a big difference.
    • Get the ENERGY STAR Guide — For complete information on keeping your home comfortable year-round, read the ENERGY STAR
      In English— A Guide to Energy-Efficient Heating and Cooling (1.38MB).

    Energy Star – U.S. Environmental Protection Agency – U.S. Department of Energy

  • Maintaining Heating and Cooling Systems

    How to Maintain Your Home’s Heating & Cooling Equipment to Save Energy

    Just like your favorite car, your heating and cooling system needs a regular trip to the mechanic to keep it purring. Without regular servicing, heating and cooling systems burn more fuel and are more likely to break down. With the proper attention, they can keep you comfortable year-round.

    Heat pumps and oil-fired furnaces need a yearly professional tune-up. Gas-fired equipment burns cleaner; it should be serviced every other year. A close inspection will uncover leaks, soot, rust, rot, corroded electrical contacts and frayed wires. In furnace (forced-air) systems, the inspection should also cover the chimney, ductwork or pipes, dampers or valves, blower or pump, registers or radiators, the fuel line and the gas meter or oil tank—as well as every part of the furnace itself.

    Next, the system should be run through a full heating cycle to ensure that it has plenty of combustion air and chimney draft. Contractors can use specialty meters to check for sufficient draft and also test the air for carbon monoxide.

    Finally, it’s time for the down and dirty task of cleaning the burner and heat exchanger to remove soot and other gunk that can impede smooth operation. For the burner, efficiency hinges on adjusting the flame to the right size and color, adjusting the flow of gas or changing the fuel filter in an oil-fired system. A check of the heat pump should include an inspection of the compressor, fan, indoor and outdoor coils and refrigerant lines. Indoor and outdoor coils should be cleaned, and the refrigerant pressure should be checked. Low pressure indicates a leak; to locate it, contractors feed tinted refrigerant into the loop and go over it with an electronic detector.

    The Low Blow

    Tuning up the distribution side of a forced-air system starts with the blower. To do the job right, it must first be removed. The axle should be lubricated, blades cleaned and blower motor checked to insure the unit isn’t being overloaded. The fan belt should be adjusted so it deflects no more than an inch when pressed. Every accessible joint in the ductwork should be sealed with mastic or a UL-approved duct tapes. Any ducts that run outside the heated space should be insulated. On a hot-water system, the expansion tank should be drained, the circulating pump cleaned and lubricated and air bled out of the radiators.

    Turn It Up

    While thermostats rarely fail outright, they can degrade over time as mechanical parts stick or lose their calibration. Older units will send faulty signals if they’ve been knocked out of level or have dirty switches. To re-calibrate an older unit, use a wrench to adjust the nut on the back of the mercury switch until it turns the system on and, using a room thermometer, set it to the correct temperature. Modern electronic thermostats, sealed at the factory to keep out dust and grime, rarely need adjusting. However, whether your thermostat is old or young, the hole where the thermostat wire comes through the wall needs to be caulked or a draft could trick it into thinking the room is warmer or colder than it really is.

    Humidifiers

    A neglected in-duct humidifier can breed mildew and bacteria, not to mention add too much moisture to a house. A common mistake with humidifiers is leaving them on after the heating season ends. Don’t forget to pull the plug, shut the water valve and drain the unit. A unit with a water reservoir should be drained and cleaned with white vinegar, a mix of one part chlorine bleach to eight parts water or muriatic acid. Mist-type humidifiers also require regular cleaning to remove mineral deposits.

    Filters

    Most houses with forced-air furnaces have a standard furnace filter made from loosely woven spun-glass fibers designed to keep it and its ductwork clean. Unfortunately, they don’t improve indoor air quality. That takes a media filter, which sits in between the main return duct and the blower cabinet. Made of a deeply-pleated, paper-like material, media filters are at least seven times better than a standard filter at removing dust and other particles. An upgrade to a pleated media filter will cleanse the air of everything from insecticide dust to flu viruses.

    Compressed, media filters are usually no wider than six inches, but the pleated material can cover up to 75 square feet when stretched out. This increased area of filtration accounts for the filter’s long life, which can exceed two years. The only drawback to a media filter is its tight weave, which can restrict a furnace’s ability to blow air through the house. To ensure a steady, strong air-flow through house, choose a filter that matches your blower’s capacity.

    Duct Cleaning

    Inside the walls and floors of 80 percent of American homes run a maze of heating and air conditioning ducts that connect each room to the furnace. As the supply ducts blow air into rooms, return ducts inhale airborne dust and suck it back into the blower. Add moisture to this mixture and you’ve got a breeding ground for allergy-inducing molds, mites and bacteria. Many filters commonly used today can’t keep dust and debris from streaming into the air and overtime sizable accumulations can form—think dust bunnies, but bigger.

    To find out if your ducts need cleaning, pull off some supply and return registers and take a look. If a new furnace is being installed, you should probably invest in a duct cleaning at the same time, because chances are the new blower will be more powerful than the old one and will stir up a lot of dust.

    Professional duct cleaners tout such benefits as cleaner indoor air, longer equipment life and lower energy costs. Clean HVAC systems can also perform more efficiently, which may decrease energy costs, and last longer, reducing the need for costly replacement or repairs. Cleaning has little effect on air quality, primarily because most indoor dust drifts in from the outdoors. But it does get rid of the stuff that mold and bacteria grow on, and that means less of it gets airborne, a boon to allergy sufferers.

  • Controlling 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.

    Three Basic Strategies

    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.

    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).

    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.

    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.

    Source: Environmental Protection Agency

  • Space Heater Safety

    The Statistics

    CPSC estimates that from 2008 to 2010, portable electric heaters were involved in approximately 1,200 fires per year.

    The Problem

    Portable electric heaters are high-wattage appliances that have the potential to ignite nearby combustible materials like curtains, beds, sofas, paper, clothing, and flammable liquids. If ignition results from a heater left on and unattended, a major fire could result.

    Safety Tips

    CPSC recommends the following for the safe use of electric heaters:

    • Never operate a heater you suspect is damaged. Before use, inspect the heater, cord, and plug for damage.
    • Follow all operation and maintenance instructions.
    • Never leave the heater operating while unattended, or while you are sleeping.
    • Keep combustible material such as beds, sofas, curtains, papers, and clothes at least 3 feet (0.9 m) from the front, sides, and rear of the heater.
    • Be sure the heater plug fits tightly into the wall outlet. If not, do not use the outlet to power the heater.
    • During use, check frequently to determine if the heater plug or cord, wall outlet, or faceplate is HOT! If the plug, outlet, or faceplate is hot, discontinue use of the heater, and have a qualified electrician check and/or replace the plug or faulty wall outlet(s). If the cord is hot, disconnect the heater, and have it inspected/repaired by an authorized repair person.
    • Never power the heater with an extension cord or power strip.
    • Insure that the heater is placed on a stable, level surface, and located where it will not be knocked over.
    • When purchasing a heater, ask the salesperson whether the heater has been safety-certified. A certified heater will have a safety certification mark.
    • Never run the heater’s cord under rugs or carpeting. This can damage the cord, causing it and nearby objects to burn.
    • To prevent electrical shocks and electrocutions, always keep electric heaters away from water, and NEVER touch an electric heater if you are wet.
    • SPREAD THE NEWS! Inform family, friends, and coworkers of the ways to use an electric heater more safely.

    U.S. Consumer Product Safety Commission (CPSC)

  • Extended Warranty FAQ’s

    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, Water Tank, 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
    • Ultra Violet Air Purifiers
    • Filters
    • Air Vents (water heater)
    • Back-Flow Preventers ()
    • Zone Valves ()
    • Pressure Reducing Valves (PRV) (water heater)
    • Expansion Tanks ( )
      … any item not included in ‘box’…

    Therefore, an extended warranty typically does NOT cover:

    1. 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, problem with meter, etc.). Why: The unit would have functioned correctly with power or fuel – not the fault of manufacturer.
    2. 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.
    3. Failure caused by exhaust or air intake vent blockage – failure caused by factor outside of manufacturer control.
    4. 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).
    5. Failures caused by acts of God, natural disasters, abuse and anything acting upon the equipment beyond the control of the manufacturer.
    6. Loss of performance or aesthetics.

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

    Maintenance agreement benefits are provided for the systems for which maintenance is provided.

    • An agreement that provides maintenance for the furnace only does not provide discounts for a cooling problem.
    • An agreement that provides maintenance for the air conditioner only does not provide discounts for a heating problem.
    • The same goes for other maintenance agreement products (coverage is extended only to the specific product(s) identified in the agreement)

    What about furnace blower failures in a no cooling situation? Cross-over situations require that both furnace and air conditioner maintenance be performed in order to be eligible for benefits.

  • Asthma Causes & Triggers

    Clearing Your Home of Asthma Triggers

    Asthma is a serious lung disease. During an asthma attack, the airways get narrow, making it difficult to breathe. Symptoms of asthma include wheezing, shortness of breath, and coughing. Asthma can even cause death.

    If you have asthma or a child with asthma, you are not alone. About 17 million Americans have asthma. Asthma is the leading cause of long-term illness in children.

    The air that children breathe can make a difference. Asthma may be triggered by allergens and irritants that are common in homes. To help your child breathe easier, consult a doctor and take precautions to reduce asthma triggers in your home.

    Here are some common triggers:

    Secondhand Smoke. Asthma can be triggered by the smoke from the burning end of a cigarette, pipe, or cigar and the smoke breathed out by a smoker. Choose not to smoke in your home or car and do not allow others to do so either.

    Dust Mites. Dust mites are too small to be seen but are found in every home. Dust mites live in mattresses, pillows, carpets, fabric-covered furniture, bed-covers, clothes, and stuffed toys. Wash sheets and blankets once a week in hot water. Choose washable stuffed toys, wash them often in hot water, and dry thoroughly. Keep stuffed toys off beds. Cover mattresses and pillows in dust-proof (allergen-impermeable) zippered covers.

    Pets. Your pet’s skin flakes, urine, and saliva can be asthma triggers. Consider keeping pets outdoors or even finding a new home for your pets, if necessary. Keep pets out of the bedroom and other sleeping areas at all times, and keep the door closed. Keep pets away from fabric-covered furniture, carpets, and stuffed toys.

    Molds. Molds grow on damp materials. The key to mold control is moisture control. If mold is a problem in your home, clean up the mold and get rid of excess water or moisture. Lowering the moisture also helps reduce other triggers, such as dust mites and cockroaches. Wash mold off hard surfaces and dry completely. Absorbent materials, such as ceiling tiles and carpet, with mold may need to be replaced. Fix leaky plumbing or other sources of water. Keep drip pans in your air conditioner, refrigerator, and dehumidifier clean and dry. Use exhaust fans or open windows in kitchens and bathrooms when showering, cooking, or using the dishwasher. Vent clothes dryers to the outside. Maintain low indoor humidity, ideally between 30-50% relative humidity. Humidity levels can be measured by hygrometers which are available at local hardware stores.

    Pests. Droppings or body parts of pests such as cockroaches or rodents can be asthma triggers. Do not leave food or garbage out. Store food in airtight containers. Clean all food crumbs or spilled liquids right away. Try using poison baits, boric acid (for cockroaches), or traps first before using pesticide sprays. If sprays are used, limit the spray to infested area. Carefully follow instructions on the label. Make sure there is plenty of fresh air when you spray, and keep the person with asthma out of the room.

    Not all of the asthma triggers addressed here affect every person with asthma. Not all asthma triggers are listed here. See your doctor or health care provider for more information.

    Also, house dust may contain asthma triggers. Remove dust often with a damp cloth, and vacuum carpet and fabric-covered furniture to reduce dust build-up. Allergic people should leave the area being vacuumed. Using vacuums with high efficiency filters or central vacuums may be helpful. When your local weather forecast announces an ozone action day, stay indoors as much as possible.

    For more information, U.S. Environmental Protection Agency, http://www.epa.gov/iaq or call EPA Indoor Air Quality Information Clearinghouse at (800) 438-4318 or the National Asthma Education and Prevention Program Guidelines for the Diagnosis and Management of Asthma at (301) 592-8573.

    Source: Environmental Protection Agency

  • System Support & Accessories

    A Guide to Indoor Air Quality

    Indoor Air Quality Concerns

    All of us face a variety of risks to our health as we go about our day-to-day lives. Driving in cars, flying in planes, engaging in recreational activities, and being exposed to environmental pollutants all pose varying degrees of risk. Some risks are simply unavoidable. Some we choose to accept because to do otherwise would restrict our ability to lead our lives the way we want. And some are risks we might decide to avoid if we had the opportunity to make informed choices. Indoor air pollution is one risk that you can do something about.

    In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Other research indicates that people spend approximately 90 percent of their time indoors. Thus, for many people, the risks to health may be greater due to exposure to air pollution indoors than outdoors.

    In addition, people who may be exposed to indoor air pollutants for the longest periods of time are often those most susceptible to the effects of indoor air pollution. Such groups include the young, the elderly, and the chronically ill, especially those suffering from respiratory or cardiovascular disease.

    Why a Safety Guide on Indoor Air?

    While pollutant levels from individual sources may not pose a significant health risk by themselves, most homes have more than one source that contributes to indoor air pollution. There can be a serious risk from the cumulative effects of these sources. Fortunately, there are steps that most people can take both to reduce the risk from existing sources and to prevent new problems from occurring. This safety guide was prepared by the U.S. Environmental Protection Agency (EPA) and the U.S. Consumer Product Safety Commission (CPSC) to help you decide whether to take actions that can reduce the level of indoor air pollution in your own home.

    ​Because so many Americans spend a lot of time in offices with mechanical heating, cooling, and ventilation systems, there is also a short section on the causes of poor air quality in offices and what you can do if you suspect that your office may have a problem. A glossary and a list of organizations where you can get additional information are available in this document.

    Indoor Air Quality in Your Home

    What Causes Indoor Air Problems?

    Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants.

    Pollutant Sources

    There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.

    The relative importance of any single source depends on how much of a given pollutant it emits and how hazardous those emissions are. In some cases, factors such as how old the source is and whether it is properly maintained are significant. For example, an improperly adjusted gas stove can emit significantly more carbon monoxide than one that is properly adjusted.

    Some sources, such as building materials, furnishings, and household products like air fresheners, release pollutants more or less continuously. Other sources, related to activities carried out in the home, release pollutants intermittently. These include smoking, the use of unvented or malfunction-ing stoves, furnaces, or space heaters, the use of solvents in cleaning and hobby activities, the use of paint strippers in redecorating activities, and the use of cleaning products and pesticides in housekeeping. High pollutant concentrations can remain in the air for long periods after some of these activities.

    Amount of Ventilation

    If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems. Unless they are built with special mechanical means of ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can “leak” into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered “leaky.”

    How Does Outdoor Air Enter a House?

    Outdoor air enters and leaves a house by: infiltration, natural ventilation, and mechanical ventilation. In a process known as infiltration, outdoor air flows into the house through openings, joints, and cracks in walls, floors, and ceilings, and around windows and doors. In natural ventilation, air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind. Finally, there are a number of mechanical ventilation devices, from outdoor-vented fans that intermittently remove air from a single room, such as bathrooms and kitchen, to air handling systems that use fans and duct work to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little infiltration, natural ventilation, or mechanical ventilation, the air exchange rate is low and pollutant levels can increase.

    What If You Live in an Apartment?

    Apartments can have the same indoor air problems as single-family homes because many of the pollution sources, such as the interior building materials, furnishings, and household products, are similar. Indoor air problems similar to those in offices are caused by such sources as contaminated ventilation systems, improperly placed outdoor air intakes, or maintenance activities.

    Solutions to air quality problems in apartments, as in homes and offices, involve such actions as: eliminating or controlling the sources of pollution, increasing ventilation, and installing air cleaning devices. Often a resident can take the appropriate action to improve the indoor air quality by removing a source, altering an activity, unblocking an air supply vent, or opening a window to temporarily increase the ventilation; in other cases, however, only the building owner or manager is in a position to remedy the problem. (See the section “What to Do If You Suspect a Problem”) You can encourage building management to follow guidance in EPA and NIOSH’s Building Air Quality: A Guide for Building Owners and Facility Managers. To obtain the loose-leaf format version of the Building Air Quality, complete with appendices, an index, and a full set of useful forms, and the newly released, Building Air Quality Action Plan, order GPO Stock # 055-000-00602-4, for $28, contact the: Superintendent of Documents, U.S. Government Printing Office (GPO), P.O. Box 371954, Pittsburgh, PA 15250-7954, or call (202) 512-1800, fax (202) 512-2250.

    Improving the Air Quality in Your Home

    Indoor Air and Your Health

    Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later.

    Immediate effects may show up after a single exposure or repeated exposures. These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable. Sometimes the treatment is simply eliminating the person’s exposure to the source of the pollution, if it can be identified. Symptoms of some diseases, including asthma, hypersensitivity pneumonitis, and humidifier fever, may also show up soon after exposure to some indoor air pollutants.

    The likelihood of immediate reactions to indoor air pollutants depends on several factors. Age and preexisting medical conditions are two important influences. In other cases, whether a person reacts to a pollutant depends on individual sensitivity, which varies tremendously from person to person. Some people can become sensitized to biological pollutants after repeated exposures, and it appears that some people can become sensitized to chemical pollutants as well.

    Certain immediate effects are similar to those from colds or other viral diseases, so it is often difficult to determine if the symptoms are a result of exposure to indoor air pollution. For this reason, it is important to pay attention to the time and place the symptoms occur. If the symptoms fade or go away when a person is away from the home and return when the person returns, an effort should be made to identify indoor air sources that may be possible causes. Some effects may be made worse by an inadequate supply of outdoor air or from the heating, cooling, or humidity conditions prevalent in the home.

    Other health effects may show up either years after exposure has occurred or only after long or repeated periods of exposure. These effects, which include some respiratory diseases, heart disease, and cancer, can be severely debilitating or fatal. It is prudent to try to improve the indoor air quality in your home even if symptoms are not noticeable. More information on potential health effects from particular indoor air pollutants is provided in the section, “A Look at Source-Specific Controls.”

    While pollutants commonly found in indoor air are responsible for many harmful effects, there is considerable uncertainty about what concentrations or periods of exposure are necessary to produce specific health problems. People also react very differently to exposure to indoor air pollutants. Further research is needed to better understand which health effects occur after exposure to the average pollutant concentrations found in homes and which occur from the higher concentrations that occur for short periods of time.

    The health effects associated with some indoor air pollutants are summarized in the section “Reference Guide to Major Indoor Air Pollutants in the Home.”

    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

    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.

    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.

    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.

    Source: Consumer Product Safety Commission

  • Energy Efficiency Ratings & Terms

    Efficiency Ratings

    The materials from which a building is constructed, as well as the systems and appliances installed there can dramatically affect the amount of energy that a building will consume over its lifetime. To help customers compare the potential impact of one to another, efficiency ratings have been devised for many building components and energy systems.

    A variety of energy ratings now abound, which can be confusing to the consumers these ratings were intended to help. We will try here to end that confusion by explaining each of the ratings systems listed below in as simple a way as possible. Also included is a Glossary of Efficiency Terms.

    Building Materials

    The materials from which a building is constructed can have a marked impact on the structure’s efficiency. Materials that allow a lot of heat to pass through them lower the overall efficiency level of the building. Conversely, materials that resist a significant amount of heat transference can help ensure greater efficiency. The degree to which a building component (such as a window or wall system) transfers heat is referred to as its U-value. The ability of an individual material (for instance, glass, wood, metal) to resist heat transfer is called its R- value.

    Appliances and Equipment

    When referring to the efficiency of an appliance or energy system, we are actually talking about how much energy that system must use to perform a certain amount of work. The higher its energy consumption per unit of output, the less efficient the system is. For example, an air conditioner that requires 750 watts of electricity to provide 6,000 Btu of cooling will be less efficient than one that can provide the same amount of cooling for only 500 watts. The most common ratings applied to energy systems are EER and SEER for most central cooling systems; COP for some heat pumps and chillers; HSPF for heat pumps in their heating modes; and AFUE for gas furnaces

    For more detailed explanations of the efficiency terms mentioned above, select any of the underlined topics below.

    Glossary of Efficiency Terms

    AFUE (annual fuel utilization efficiency): an efficiency rating that measures the efficiency with which gas and other fossil-fuel-burning furnaces use their primary fuel source over an entire heating season. It does not take into account the efficiency with which any component of the system, such as a furnace fan motor, uses electricity. AFUE is expressed as a percentage that indicates the average number of Btu worth of heating comfort provided by each Btu worth of gas (or other fossil fuel) consumed by the system. For instance, a gas furnace with an AFUE of 80% would provide 0.8 Btu of heat for every Btu of natural gas it burned.

    When comparing efficiencies of various gas furnaces, it is important to consider the AFUE, not the steady state efficiency. Steady state refers to the efficiency of the unit when the system is running continuously, without cycling on and off. Since cycling is natural for the system over the course of the heating season, steady state doesn’t give a true measurement of the system’s seasonal efficiency. For instance, gas furnaces with pilot lights have steady-state efficiencies of 78% to 80%, but seasonal efficiencies B AFUEs B closer to 65%.

    Virtually all gas forced-air furnaces installed in this area from the 1950s through the early 1980s had AFUEs of around 65%. Today, federal law requires most gas furnaces manufactured and sold in the U.S. to have minimum AFUEs of 78%. (Mobile home furnaces and units with capacities under 45,000 Btu are permitted somewhat lower AFUEs.) Gas furnaces and now on the market have AFUEs as high as 97%

    Air infiltration: the introduction, usually unintentional, of unconditioned outdoor air into a mechanically heated and/or cooled building. Air infiltration can occur through any opening in the home’s structure, including seams where walls meet other walls, window or door frames, or chimneys; holes where wires or pipes penetrate walls, floors or ceilings/roofs; and between the loose-fitting meeting rails of double-hung windows or a door door bottom and door threshold. It is one of the major cause of unwanted heat gain and loss and personal discomfort in buildings.

    Btu (British thermal unit): a measurement of the energy in heat. It takes one Btu of heat to warm one pound of water by 1° Fahrenheit. Btu can be used either to define an air conditioner’s cooling capacity (i.e., the number of Btu of heat that can be removed by the system) or a furnace’s heating capacity (i.e., the number of Btu of heat that can be supplied by the system).

    Caulk: a substance used to seal air infiltration points between two immovable objects, such as where exterior or interior wall surfaces meet window or door frames and at corners formed by siding. Most caulks come in tubes and are applied with the use of a special caulk “gun.”

    Compact fluorescent lamps (CFLs): a light “bulb” using fluorescent technology but designed to be used on many of the same fixtures traditionally used by standard incandescent “A” bulbs. They incorporate a small-diameter looped or swirled tube that is attached to a screw-in base. CFLs provide light levels comparable to 20- to 150-watt incandescent bulbs for 70% to 75% less energy. They also last 10 to 13 times longer than equivalent incandescent bulbs.

    Conduction: the transfer of heat through solid objects such as glass, dry wall, brick and other building materials. The greater the difference between the outdoor and indoor temperatures, the faster conduction can occur and the more home a building can gain or lose.

    Convection: the transfer of heat to or from a solid surface via a gas or liquid current. Where home heat loss and gain are concerned, heat convection is caused by air (gas) currents that carry heat from your body, furniture, interior walls and other warm objects to windows, floors, ceilings, exterior walls and other cool surfaces.

    COP(coefficient of performance): a measurement of a heat pump’s efficiency (in the heating mode) at a specific outdoor temperature – usually 47°F. A COP of 1 indicates that for each unit of energy being used, an equal amount of energy, in the form of heat) is being provided by the system. A heat pump with a COP of 3 would provide three times as much energy in heat as it consumes in electricity at an outdoor temperature of 47°F. COP is also sometimes used to measure the single temperature cooling efficiency of chillers.

    This formula is stated:

    COP =Btu of heat produced at 47°FBtu worth of electricity used at 47°

    For instance, let’s assume a heat pump uses 4000 watts of electricity to produce 42,000 Btu per hour (Btu/hr) of heat when it is 47°F outside. To determine its COP, you would first convert the 4000 watts of electrical consumption into its Btu/hr equivalent by multiplying 4000 times 3.413 ( the number of Btu in one watt-hour of electricity). Then you would divide your answer — 13,648 Btu/hr — into the 42,000 Btu/hr heat output. This would show your heat pump to have a 47°F COP of 3.08. This means that, for every Btu of electricity the system uses, it will produce a little more than three Btu of heat when the outdoor temperature is 47°F.

    The second formula is most frequently used to determine chiller efficiency. Using this calculation method, you would div 3.516 by the number of kilowatts (kW) per ton used by the system. This formula is stated:

    COP =3.516kW/ton

    For example, a chiller that consumes 0.8 kW per ton of capacity would have a COP of 4.4 (3.516 divided by 0.8). On the other hand, the COP of a new, more efficient chiller, using as little as 0.5 kW per ton, would be greater than 7 (3.516 divided by 0.5).

    Daylighting: the technique of using natural light from windows, skylights and other openings to supplement or replace a building’s artificial lighting system. When applied properly, daylighting can reduce a facility’s lighting costs. When applied improperly, however, it can not only lead to inappropriate light levels but can also raise the building’s cooling costs by introducing high levels of solar heat into the interior of the building.

    Dedicated fixture: a lighting apparatus that is designed specifically for use with a particular type of lamp (bulb). For example, the increasing popularity of CFLs has led to the development of a growing number of fixtures – including torchieres, table lamps, ceiling drums, and recessed canisters – dedicated solely for use with compact fluorescents.

    EER (energy efficiency ratio): a measurement of the energy required by a cooling system as it attempts to maintain indoor comfort at a specific outdoor temperature – usually 95°F. The term EER is most commonly used when referring to window air conditioners and geothermal heat pumps.

    EER equals the number of Btu per hour worth of cooling provided at the specified outdoor temperature divided by the number of watts used to provide that level of cooling.

    The formula for calculating EER is:
    EER =

    Btu/hr of cooling at 95°
    ——————————
    watts used at 95°

    For instance, if you have a window air conditioner that draws 1500 watts of electricity to produce 12,000 Btu per hour of cooling when the outdoor temperature is 95°, it would have an EER of 8.0 (12,000 divided by 1500). A unit drawing 1200 watts to produce the same amount of cooling would have an EER of 10 and would be more energy efficient.

    Using this same example, you can see how efficiency can affect a system’s operating economy. First, you’ll need to determine the total amount of electricity — measured in kilowatt-hours — the unit will consume over a period of time. (A kilowatt-hour is defined as 1,000 watts used for one hour. This is the measure by which your monthly utility bills are calculated.) To do this, let’s assume you operate your 8 EER window air conditioner — drawing 1500 watts at any given moment — for an average of 12 hours every day during the summer. At this rate, it will use 18,000 watt-hours, or 18 kilowatt-hours (kWh) each day, leading to a total consumption of 540 kWh over the course of a 30-day month. At a summer electric rate of 6.34¢ per kWh, it would cost you $34.24 to operate that window air conditioner each month. At the same time, a 1200-watt, 10 EER system, consuming 14.4 kilowatt-hours per day and 432 kWh per month, would cost you $27.39, a 20% savings over the less efficient model.

    Efficiency: the degree to which a certain action or level of work can be effectively produced for the least expenditure of effort or fuel. For instance, a light bulb that uses 15 watts of electricity to produce 900 lumens of light would operate with much greater efficiency than one that required 60 watts to produce the same light level.

    HSPF (heating seasonal performance factor): a measurement of an all-electric air-to-air heat pump’s efficiency (in the heating mode) over an entire season. HSPF is calculated by dividing the total number of Btus of heating provided over the entire season by the total number of watt-hours required to operate the system over the season.

    The formula is written:

    HSPF =

    Btu of heat produced over the heating season
    ——————————————————————-
    watt-hours of electricity used over the heating season

    Most heat pumps installed in Springfield today have HSPFs in the 7.0 to 8.0 range, meaning they operate with seasonal efficiencies of anywhere from 205% to 234%. (To convert the HSPF number into a percentage, you just divide the HSPF by 3.414, the number of Btu in one watt-hour of electricity.) That means that, for every Btu-worth of energy they use over the entire heating season, these systems will put out anywhere from 2.05 to 2.34 Btu of heat. Compare this to electric furnaces, which have nominal efficiencies of 100% (for each Btu worth of electricity, they put out one Btu of heat), or new gas furnaces, which have efficiency ratings of about 80% to 97% (for each Btu worth of gas, they put out 0.8 to 0.97 Btu of heat).

    NOTE:When comparing energy systems that use different primary fuel sources with different costs per Btu, it is important that you understand that higher operating efficiency is not necessarily equivalent to better operating economy. Although an electric heat pump might work with greater efficiency than a gas furnace, it won’t necessarily be more economical to run due to the pricing difference between the two fuel sources.

    Insulation: a product that inhibits conductive and convective heat transfer. Some materials are naturally better insulators than others because they contain more “dead air” pockets. These pockets of trapped gas help to slow the movement of heat. However, if processed properly, virtually any product, including glass, cotton, paper, and plastic, can be used to make insulation.

    Internal Heat Gain: the accumulation of heat produced by a building’s energy systems and appliances and occupants. Depending on the number of occupants and the type and number of energy systems used during the day, it’s not unusual for internal heat gain to account for 20% of a home’s total summer cooling load.

    Kilowatt (kW): 1000 watts.

    Kilowatt-hour (kWh): 1000 watts used for one hour – or any combination of energy multiplied by time that is equivalent to that rate of electrical consumption, such as one watt used for 1000 hours, 10 watts used for 100 hours, or 50 watts used for 20 hours. For example, a 100-watt light bulb left on for five hours each day would consume one kWh every two days. Kilowatt-hour is the primary measure on which U.S. electric companies base most customer billing. CWLP residential customers pay an average of 5.5¢ to 6¢ per kWh of electricity used.

    Low-e: refers to a material designed to reduce the amount of radiant heat that can be transferred through glass or other translucent window coverings. Low-e (which stands for low-emissivity) coatings or films have the ability to re-radiate a high percentage of heat back toward its source. In summer low-e windows can be effective in reducing the amount of solar heat that can enter a house, and in winter they can reduce the amount of furnace-generated heat that can be lost to the outdoors.

    Lumen: a unit of light given off by a light source. Lumen is the measurement used to compare the levels of illumination provided by different light sources.

    Payback period: the amount of time it takes to achieve a full return on an investment. For instance, if a high-efficiency air conditioner would cost you $300 more to purchase than a lower-efficiency model but would save you $100 a year in operating costs, your payback period on the extra $300 investment would be three years.

    Radiation: a method of heat transfer in which heat is transmitted from surface to surface via infrared waves. Radiant heat warms the surfaces it touches without increasing the temperature of the air through which it travels. All warm bodies radiate infrared energy.

    Return on investment (ROI): the annual rate at which an investment earns income. It is calculated by dividing the annual earnings by the investment. For instances, a bank savings account paying $3 per year per $100 investment has an ROI of 3% ($3 / $100). An efficiency investment’s ROI comes not from money paid to you, but rather from money saved by you on your energy bills.

    R-value: a measurement of a material’s ability to resist heat transfer. Insulation products are rated according to the R-value. The higher its R-value, the greater the product’s ability to resist heat flow will be.

    Some materials are more resistant to heat transfer than others, giving them higher R-values. One of the best ways to enhance the product’s R-value is to increase the amount of gas (including air) inside or immediately surrounding it. For instance, the glass of a single-pane window has virtually no R-value, but the thin film of air that normally exists on either side of the glass gives the window an R-value of about 0.83. Adding a second pane of glass and sealing the space between the panes will increase the thickness of one of the insulating gas layers, thereby more than doubling the window’s R-value.

    Another example of how the presence of dead-air spaces affect a product’s R-value can be seen with wood. Hard woods, like oak, typically have an insulating value of R-1 per inch of thickness. However, softer woods, such as pine, might have R-values twice as high due to their greater number of air-filled pores.

    Products developed especially for the purpose of impeding unwanted heat transfer are called insulation. Insulation can be made of a variety of materials, including old newspapers and wood fibers, glass fibers, and synthetic foams. It can also come in a variety of configurations, including soft blankets, rigid boards, or fluffy granular loose-fill, but what they all have in common, is their abundance of air-filled pores or pockets.

    The actual R-value of insulation products can vary greatly, depending on their composition and form. The least resistant and least common are perlite and vermiculite loose-fills, at R-2.2 to R-2.7 per inch of thickness; the most resistant are polyisocyanurate rigid boards, at R-7 per inch of thickness. Fiberglass blankets and cellulose loose-fills, two of the most common residential insulations have R-values of 3.1 to 3.7 per inch.

    SEER (seasonal energy efficiency ratio): a measurement of how energy efficient a central cooling system can operate over the course of an entire cooling season. This term is most often applied to central air-to-air heat pumps (in the cooling mode) and air conditioners. SEER is expressed as the dividend of the number of Btu of cooling provided over the season divided by the total number of watt-hours the system consumes. Federal law requires all central split systems now made and sold in the United States to have minimum SEERs of 10. Effective January 2015, the minimum for most systems will increase to 14.

    SEER is calculated based on the total amount of cooling (in Btu) the system will provide over the entire season divided by the total number of watt-hours it will consume:

    SEER =

    seasonal Btu of cooling
    ———————————-
    seasonal watt-hours used

    By federal law, every central split cooling system manufactured or sold in the U.S. today must have a seasonal energy efficiency ratio of at least 10.0.

    Settled density: the amount (depth) of insulation remaining after it has had a chance to settle. This term is most often applied to loose-fill insulation’s—particularly those made of cellulose. To ensure loose-fill cellulose insulation will maintain its desired insulating value (r-value) once it has settled, you will need to install it to a depth that is 20% to 25% deeper than your settled density r-value actually calls for.

    Solar Gain: heat that builds up inside a structure as a result of sunlight that enters through transparent or translucent surfaces, such as windows, and is converted to heat after striking other surfaces inside the building. In summer, solar gain can cause as much as 50% of the interior heat gain in a home.

    Thermostat Setback: an intentional effort to control building energy consumption by manually or automatically controlling thermostat settings according to the amount of cooling or heat that is needed at any given time of the day or night.

    U-value: the measurement of how readily heat can flow through glass, brick, drywall and other building materials. U-values, which are expressed in decimals(e.g., U-0.166), are the opposite of R-values. The higher the U-value, the less efficient the building material will be.The lower a material’s U-value, the higher its R-value will be.

    To determine the R-value of a product for which the U-value is given, you first convert the U-value to its equivalent fraction and then invert it. For instance, the equivalent fraction of U-0.166 would be 166/1000 or 1/6. This inverts to 6/1 or 6, giving you an R-value of 6.

    For most consumers, U-value is likely to be of concern only when shopping for new windows, where efficiency is frequently stated in terms of U-value rather than R-value.

    Vapor barrier: a material designed to resist the migration of moisture through a wall or other building component. As water vapor in the air moves from a warmer to a cooler part of the building it can settle and condense on cooler building components, such as rafters, beams and walls, eventually causing those components to mildew, rust or rot. Vapor barriers, which are impermeable to water vapor migration, help to protect against this possibility. The most common vapor barriers are made of plastic, but other materials, including oil paint, can also serve the purpose.

    Watt: a unit of electric power. The amount of power required by electric appliances is expressed in watts.

    Watt-hour: a unit of electric energy, equal to one watt used over a period of one hour.

    Weatherstripping: a product designed to seal the cracks that exist between two moving parts or one moving and one stationary part of windows, doors and other movable building components. Weatherstripping is used to improve a building’s energy efficiency by preventing the unintentional entry of unconditioned outdoor air.

  • Carbon Monoxide Questions and Answers

    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, lawn mowers, 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, 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 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 owners 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 un-vented 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 air flow 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 head count 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 HVAC contractor 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 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 tow-able recreational vehicles that have a generator or are prepped for a generator.

    U.S. Consumer Product Safety Commission (CPSC)