The information provided here is based on current scientific and technical understanding of the issues presented. Following the advice given will not necessarily provide complete protection in all situations or against all health hazards that may be caused by indoor air pollution. There are three basic strategies to improve indoor air quality 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. For most indoor air quality problems in the home, source control is the most effective solution. 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). Ventilation and shading can help control indoor temperatures. Ventilation also helps remove or dilute indoor airborne pollutants coming from indoor sources. This reduces the level of contaminants and improves indoor air quality (IAQ). Carefully evaluate using ventilation to reduce indoor air pollutants where there may be outdoor sources of pollutants, such as smoke or refuse, nearby.air handling unit start-up procedure The introduction of outdoor air is one important factor in promoting good air quality. cost of hvac in new homeAir may enter a home in several different ways, including:ac unit pull out switch Infiltration occurs in all homes to some extent.

Natural ventilation describes air movement through open windows and doors. If used properly natural ventilation can at times help moderate the indoor air temperature, which may become too hot in homes without air-conditioning systems or when power outages or brownouts limit or make the use of air conditioning impossible. Natural ventilation can also improve indoor air quality by reducing pollutants that are indoors. Examples of natural ventilation are: Most residential forced air-heating systems and air-conditioning systems do not bring outdoor air into the house mechanically, and infiltration and natural ventilation are relied upon to bring outdoor air into the home. Advanced designs for new homes are starting to add a mechanical feature that brings outdoor air into the home through the HVAC system. Some of these designs include energy efficient heat recovery ventilators to mitigate the cost of cooling and heating this air during the summer and winter. 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. Indoor air quality can be worse than that of outdoor air. Problems can arise from moisture, insects, pets, appliances, radon, materials used in household products and furnishings, smoke, and other sources.

Effects range from minor annoyances to major health risks. Remedies include ventilation, cleaning, moisture control, inspections, and following manufacturers' directions when using appliances and products. unusual and noticeable odors; stale or stuffy air; a noticeable lack of air movement; dirty or faulty central heating or air-conditioning equipment; damaged flue pipes and chimneys; unvented combustion air sources for fossil-fuel appliances; the presence of molds and mildew; adverse health reaction after remodeling, weatherizing, bringing in new furniture, using household and hobby products, and moving into a new home; feeling noticeably healthier outside. moisture and biological pollutants, such as molds, mildew, dust mites, animal dander, and cockroaches; high humidity levels, inadequate ventilation, and poorly maintained humidifiers and air conditioners; combustion products, including carbon monoxide, from unvented fossil-fuel space heaters, unvented gas stoves and ovens, and back-drafting from furnaces and water heaters;

formaldehyde from durable-press draperies and other textiles, particleboard products, such as cabinets and furniture framing, and adhesives; radon, which is a radioactive gas from the soil and rock beneath and around the home's foundation, groundwater wells, and some building materials; household products and furnishings, such as paints, solvents, air fresheners, hobby supplies, dry-cleaned clothing, aerosol sprays, adhesives, and fabric additives used in carpeting and furniture, which can release volatile organic compounds (VOCs); asbestos, which is found in most homes more than 20 years old. Sources include deteriorating, damaged and disturbed pipe insulation, fire retardant, acoustical material (such as ceiling tiles) and floor tiles; lead from lead-based paint dust, which is created when removing paint by sanding, scraping and burning; particulates from dust and pollen, fireplaces, wood stoves, kerosene heaters and unvented gas space heaters; tobacco smoke, which produces particulates, combustion products and formaldehyde.