Using the Tool

Local governments can improve air improve quality, public health and productivity by developing and adopting IAQ policies for public buildings. They can also support private and institutional sector efforts by encouraging green building techniques and green property management procedures both for nonresidential and residential buildings to improve air quality and public health. Indoor air quality is influenced by decisions made at the building design and construction stages, as well as through day-to-day living choices made by each building owner, operator, occupant and visitor. Improvements to indoor air quality are focused on three basic strategies, outlined by the EPA’s Indoor Environments Division (IED); Source Control, Ventilation Improvements, and Air Cleaners. Approaches to implementing these strategies vary across building type, location, and scale, but the basic components remain consistent:

• Source Control
  • The most effective way to improve indoor air quality is usually to eliminate sources of pollution or reduce their emissions. Some sources, including materials 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. In construction and renovation, the selection of materials with low-emitting products, formaldehyde-free materials, and using only low-toxicity and low-emitting paint also help eliminate sources of indoor air pollution.
  • In nonresidential structures, source control can be achieved by conducting regular building walkthrough inspections, including routine moisture inspections. Building owners, property managers, and tenants should adopt mold prevention and remediation policies and plans. Indoor humidity levels should be maintained between 30% and 60%. Commercial and institutional property management teams should be testing periodically for radon and making the necessary mitigations to eliminate any negative impacts. These managers should also implement a hazardous materials plan that includes instructions for appropriate usage, labeling, storage, and disposal. Chemical management and inventory plans are also effective in controlling the source of indoor air pollution, as well as the practice of conducting any necessary pollutant-releasing activities during times when the building is unoccupied. The implementation and enforcement of smoke free and anti-idling policies can have a significant impact on negative effects of outdoor air on indoor air.
• Ventilation Improvements
  • Concentrations of indoor air pollutants can also be reduced by increasing the amount of outdoor air flow through a building. 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. New homes with advanced designs sometimes feature mechanical systems that bring outdoor air into the home, including energy-efficient heat recovery ventilators, also known as air-to-air heat exchangers.
  • In commercial and larger scale facilities management, including schools, this includes establishing a maintenance plan that calls for regular HVAC system inspections, requires regular filter changes, and checks to ensure condensate pans are draining. As a practice, outdoor air ventilation should be provided in accordance with ASHRAE Standard or local code (e.g., clean air supply diffusers, return registers, and outside air intakes). In practice, all unit ventilators should be kept clear of books, papers, and other items.
• Air Cleaners
  • The US Consumer Product Safety Commission identifies several types and sizes of air cleaners on the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems. Although some air cleaners are highly effective at particle removal, most are 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.)