Readers wrote me with questions about air purification in their home. Here’s the latest on actions you can take to improve indoor air quality.
“I’ve heard of a HEPA filter for air conditioning. What is this and should I buy one?”
HEPA stands for High-Efficiency Particulate Air. A HEPA filter works with a powerful fan to force air through a thick pleated mesh that traps pollen, pet dander, dust mites, and smoke. It can filter out nearly all toxic microorganisms including bacteria, mold spores and viruses. Hospitals are one of the largest users of HEPA air filters.
Sounds great, right? Let’s run down to the store and buy one. Wait, not so fast. There are a couple of problems you’ll encounter if you try to put a HEPA filter in your air handler or at the air return ducts. The first one is expense – ten dollars for a vacuum cleaner size filter, and over $200 for commercial air handlers. The second problem is that residential air handlers do not have fans with enough power to push air through HEPA type media.
But there is some good news – since the point of using a fancy filter is to clean the air, there are things you can do to improve the air quality inside. One is to use a HEPA filter in your vacuum cleaner if it is a model that is designed to use HEPA filtration. The other thing you can do is purchase a standalone air purifier, which I’ll cover in a future article.
Without moving to a dedicated air purifier, the following things will help you keep indoor air fresh and clean.
A well-maintained vacuum cleaner, with a HEPA filter, used several times a week on floors and carpets will go a very long way in keeping your home air clean. A non-HEPA vacuum with dirty filters, on the other hand, will actually add dirt and contaminants to the air by picking it up off the floor and re-distributing it into the air.
Changing your air conditioning and heating filters on a schedule, and using high-efficiency air filters. The mid to high-efficiency air conditioning filters sold at the grocery store are very good at trapping nasty particles.
Minimize the use of candles and wood fires if you can. These add to the indoor pollutant load.
Limit use of air fresheners and strong cleaning products.
Don’t smoke indoors.
Use exhaust fans if you have them when you’re cooking, but don’t use them if you have a wood fire going in the fireplace. The fan can draw smoke into the living area from the fireplace.
You can also call an air conditioning contractor to come to your home and quote upgrading your air handler fan to one that will handle a HEPA installation. This is not an inexpensive upgrade, so you may want to try the methods above first, and then consider a standalone air purifier.
Opening windows on nice days will go a long way in cleaning your indoor air. With the Environmental Protection Agency claiming that indoor air is two to five times more polluted than outdoor air, letting the breeze sweep out pollutants will reduce your task list.