9.8   Air Filtration for Indoor Air Quality

Efficient air filters can reduce particle pollution in homes where particles are a air-quality problem. Ventilation isn’t effective at removing small particles. Suggest that customers run their air handlers during heavy air pollution in cities, proximity to dirt roads, seasonal forest fires, and other particle-generating events.

You can run an air-handler fan using the “fan only” setting on a thermostat. You can even program the fan to run for a period each day using a programmable thermostat.

The best places for filters are in forced-air HVAC systems or in balanced ventilation systems. Room air cleaners can also be effective particle removers if there is natural circulation among rooms.

Air filters affect the airflow and energy consumption of forced air HVAC systems and balanced ventilation systems. Before choosing the type of air filter and deciding to use the filter to remove particles, consider the filter’s MERV rating and a home’s need for particle removal. For more information on MERV rat­ings, see “Air Filter Effectiveness” on page 339.

9.8.1   Installing Filters for Outdoor Air

Provide filters for outdoor air supplied through ducted ventila­tion systems and observe these specifications.

✓     Select a filter with a MERV rating of 6 or greater.

✓     The filter’s pressure drop must not result in insufficient ventilation airflow.

✓     Install the filter on the inlet side of the fan.

✓     Make the filter accessible for changing or cleaning.

✓     Instruct the occupants or building manager on how and when to service the filter.