Skip to main content
King County Logo
Dec
21

Strategies to improve indoor air quality

There are many potential causes of poor indoor air quality. By addressing these causes, and using filtration and ventilation, we can all improve the quality of indoor air.

How do you know if you have an indoor air quality problem? Ask yourself if anyone in your home often does the following:

  • sneeze and cough
  • wake up congested, or with a headache
  • have an irritated throat, nose, or eyes
  • have frequent asthma episodes or respiratory infections
  • feel better when you're away from home

If the answer is yes to any of these, you may have an indoor air quality concern.

Causes of poor indoor air quality

Poor indoor air quality can be caused by:

  • Smoking indoors, smoke drifting in from outdoors, or smoke being carried indoors on clothing
  • Things that burn, such as oil, candles, gas, kerosene, charcoal briquettes, or wood
  • Central heating, cooling, or humidifying systems
  • New or recently installed building materials and furnishing. This can include carpets, and some wood pressed products
  • Household cleaning and maintenance products
  • Personal care products, like hair spray or soaps
  • Too much moisture in the house
  • Tracking pesticides and pollens in on shoes and clothes
  • Little circulation of fresh, outdoor air.

By changing your habits, such as not burning candles indoors, you can improve indoor air quality. You can also use ventilation and filtration strategies to help!

Ventilation

Ventilation pulls fresh outside air into indoor spaces to reduce the amount of airborne pollutants, such as viruses.
These actions can improve ventilation in your space:

  • Open windows and doors to bring in more outside air when it is safe.
  • Place portable fans as close as possible to open windows to blow potentially contaminated air out. Be sure the fans are pointing outside.
  • Run exhaust fans like bathroom fans or kitchen hoods whenever the building is occupied.
  • If you have a Heating, Ventilation, and Cooling (HVAC) system:
    • Create a schedule for regular HVAC inspections, cleaning and maintenance. Include filter replacements, and system upgrades or improvements, as needed.
    • Open dampers (moveable vents) to let in more outside air. Try to increase the amount of indoor air it pulls in to 100%.
    • If possible, upgrade the filter in your HVAC system to MERV 13 or the highest rating your system allows.

Filtration

Filtration removes viruses and pollutants from the air by trapping them in a filter.
To increase filtration, use portable HEPA-equipped air cleaners. HEPA stands for High Efficiency Particulate Air. Here are some tips for selecting and using HEPA air cleaners:

  • Use AHAM verified and/or CARB certified cleaners.
  • Read our HEPA air cleaner guidance to determine the number you may need, or use the Portable Air Cleaner Purification Calculator from the Harvard Healthy Buildings Program. Keep it on – aim for the highest setting to achieve the cleanest air quality, but if it is too loud, turn it down and add additional portable HEPA air cleaners.
  • Create a cleaning and maintenance schedule that includes vacuuming the pre-filter and wiping the unit clean regularly. Additionally, make sure your schedule includes replacing filters according to the cleaner's maintenance schedule (or sooner, based on use). Regular maintenance will help the cleaner run properly.
  • Worried about energy use? Most HEPA air cleaners, on their highest setting, only use about as much energy as a light bulb.
expand_less