Becoming familiar with the normal air quality index for your location helps you make informed choices to support a healthy indoor environment in your home. Better known as the AQI, this numerical rating system designed by the Environmental Protection Agency ranges from 0 to 500 and represents the daily air quality in a specific location. The higher the AQI rating, the more particulates and pollutants are affecting local air.
For locales where the normal air quality index outdoors frequently exceeds 50, here are some strategies to keep indoor air quality healthy.
Air Filtration
Where the normal air quality index is elevated, proper air filtration plays an important role. Your HVAC contractor can explain the best air-filter choice according to the MERV (Minimum Efficiency Reporting Value) rating that represents filtration efficiency. Filters below MERV 8 are lower efficiency and remove only the largest particles, while filters between MERV 8 and MERV 13 are considered high efficiency. High-efficiency filtration removes airborne particles as small as 0.3 microns and is often the preferable choice for locales with higher-than-normal AQI.
Air Balancing and Sealing
Where the AQI frequently indicates a high level of pollutants, two strategies can help reduce infiltration into the house:
- Air balancing. When an HVAC system is properly “balanced,” indoor air pressure maintains a slightly positive pressure. When the house is unbalanced, indoor pressure is less than that outdoors. This can draw unfiltered, potentially polluted outdoor air into the house through structural cracks and gaps. Pressure imbalance may be caused by issues including excessive air loss through exhaust vents and leakage in HVAC ductwork.
- Air sealing. Outdoor air infiltration may result from worn weatherstripping around doors and windows, as well as leaks where plumbing, electrical wiring, and cables penetrate exterior walls. A qualified HVAC contractor can perform a visual inspection and blower test to determine the amount of air leakage occurring in the structure.
Ask the air-quality experts at Jackson & Sons for more about how the normal air quality index impacts your home’s indoor environment.