What is a HEPA Filter

HEPA stands for high efficiency particulate air. You may have a HEPA filter for your vacuum but did you know there are HEPA filters for furnaces? A HEPA filter is the best kind you can get, as it removes more than 99% of particles that are 0.3 microns or larger in size. However, due to the thick filtration material used in such filters, a typical residential furnace or air conditioner could not handle the intense air pressure needed to get through the material. This would restrict the flow of air from your vents and possibly even damage the unit.

The closest you can get to the high levels of HEPA filtration would be a higher MERV rating over 13.These can come pretty close to HEPA filtration levels, except they won’t remove viruses from the room. Clean rooms and hospitals would benefit from HEPA filters; for your home, you’re best off with even a MERV 8 up to an 11. Anything more is overkill. If you are intent on having HEPA filters in your home, you can install a separate air filter that allows your furnace to continue to function properly yet with the added benefits of HEPA filtration for the highest air quality.

Motor capacity is a big component of all this; you don’t want to do damage to your furnace that will cost you a lot later. You could have a specially designed and constructed HVAC system that can handle the capacity of true HEPA filters, but this goes above and beyond normal household needs.

Even the EPA agrees. They say installing a HEPA filter in an existing HVAC system would require professional modification; without it, a standard residential air-handling unit and ductwork couldn’t possibly accommodate such filters due to their size and increased airflow resistance. True HEPA filters with a MERV between 17 and 19 are can handle between 99.97 percent and 99.99 percent in removing 0.3 ìm particles, with a MERV of 20 being rated for 0.1 to 0.2 ìm particles.

In general, manufacturers of HEPA filters market their products to allergy and asthma patients. However, filters with MERV ratings between 7 and 13 are found to be just as effective as true HEPA filters in filtering out most indoor particles that could cause adverse health effects.

Here at Filtration Montreal, we stand by our recommendation of sticking with MERV 8 or 11 over 13 and higher. To spend more on filters just to get the higher number is just overkill. You’re better off purchasing MERV 8 filters and changing them more often. Not only are the higher MERV rated filters higher in price, they need to be replaced more often. That’s because they remove dust and allergens so well that they get clogged with dust much faster than a standard MERV 8. We don’t think it’s worth the investment unless you or a family member has severe allergies or asthma for extra peace of mind or you own a hospital or clean room.

Now’s a good time to place your order for furnace filters. Brrr, it’s getting cold out there!