What is a HEPA Filter?

HEPA, which means high-efficiency particulate air, filters are used, mainly in commercial and industrial uses where contamination control is required. Places or industries which frequently use HEPA filters include hospitals, medical devices and pharmaceutical production, food facilities, and schools. Is it worth it, for your home or business, to upgrade to a HEPA filter?

HEPA filters are normally composed of a fiberglass filter that traps pollutants and contaminants as they go through. The technology was put into common use starting in the 1950s. In the U.S., the standard measurement for a HEPA filter is it captures 99.97% or more of particles down to a size of 0.3 microns.

HEPA or HEPA-Type

With HEPA filters, you’ll likely see a MERV number. MERV, which means Minimum Efficiency Reporting Value, measures, and rates the performance of filters. HEPA filters typically are a MERV 17 rating, although, they can have a rating from 13-17. A “HEPA-type” or “HEPA-like” filter can have a MERV from 9-12. A filter with a MERV from 9-12 will filter out material in size from 1-3 microns. This means there is a substantial difference between a true full-grade HEPA filter and what can be labeled as HEPA-type or HEPA-like.

What are Microns?

A micron, or a micrometer, is a millionth of a meter. It’s a way to measure very small particles or contaminants such as dust, pollen, mold, bacteria, and viruses.

The human eye can see particles or other matter down to about 10 microns. The width of human hair is about 50 microns. A HEPA filter with a MERV rating of 17 filters matters down to 0.3 microns.

How Does a HEPA Filter Work?

HEPA air filters function by capturing contaminants as they go through a web of fiberglass fibers. As the toxins travel through a filter, there are four steps of filtration: Diffusion, interception, inertial impaction as well as sieving.

Larger particles are caught and held within the inertial impaction and sieving. The particles are trapped as they make contact with the fibers. The medium-sized matter is filtered by the interception fibers. The smallest matter is dissipated, then filtered by the fibers.

Benefits of HEPA Filters

HEPA filters can be very helpful and important in certain situations. People who have allergies or asthma can have major benefits from using a HEPA filter and air purifier.

HEPA filters will filter out allergens, dust, mold, pet dander, and other common breathing contaminants.

HEPA filters can help and improve your cooling and heating system by capturing dust and dirt, stopping them from developing within your system and home. The filters can be installed within an HVAC system, and/or you can put in an air purifier.

Drawbacks of HEPA Filters

As good as HEPA filters are, they have some negatives or limitations. Here are a few things to consider.

• They Can’t Stop Everything

HEPA filters will not filter everything. Hazardous pollutants such as bacteria and viruses can be smaller than 0.3 microns. There are some allergens smaller than this, too. In nearly all homes or buildings, putting in HEPA filters will improve air quality and remove nearly all contaminants, but it still won’t be 100% perfect.

• Viruses Can Still Get In

Viruses are too microscopic for HEPA filters. For a long time, manufacturers and advertisers were allowed to claim this about HEPA and other air filters. New FTC laws now forbid any company or manufacturer from making this statement.

• They Can Get Dirty

HEPA filters catch and filters out mold and bacteria. This is good, right? Yes, but in time, with a neglected or old filter, it can become an unexpected problem.

Bacteria can release toxins into the air as it dies, as in the inside of a filter. This can cause asthmatic, respiratory, or allergic reactions. HEPA filters will filter mold, but mold spores can remain alive. Most likely in warm, dry, and dark spaces, mold can grow within a HEPA filter and get out into the rest of the system and home.

How to Keep a HEPA Filter Working Well

If you have a HEPA filter in your house, but are still worried about contaminants, or keeping the filter and your HVAC system going at peak efficiency, here are a few ideas to keep in mind.

• Keep the House Clean – A HEPA or any filter can’t remove dust, dirt, mold, pollen, pet hair and so on which is already in your house.
• Where Do Pets Spend Time? – If you have rooms or areas, such as certain bedrooms, nurseries, a kitchen or bathrooms where pet dander or extra dust could be more problematic, keep pets out of those areas.
• Think about Hazardous Fumes – Think about products you’re using, maybe even for cleaning. Think about fumes from smoking or other material. Filters can’t filter VOC material in some cleaning, makeup, disinfectants or solvents.
• Good Ventilation – Outdoor air quality is usually better than indoor air quality. Opening windows and doors when possible, when the weather cooperates, often helps airflow in a home.

Are HEPA Filters Worth It?

Before putting in a HEPA filter or an air purifier with a HEPA filter, it’s good to know what to expect, and what it can and can’t help with.

HEPA filters have flaws, most specifically when dealing with gases, VOCs, and viruses. If people in your home or family have needs related to asthma or allergies, HEPA filtration for an air system can be a major benefit.

At South End Heating and Air, we specialize in HVAC repair and service agreements, call us for a free consult and free estimate. We’ll evaluate your system and help make recommendations for optimum value. After all, we want to keep you cool all summer long and warm in the winter. Just schedule a visit with one of our technicians to talk about how we can help with your heating needs. Would you like to learn more options our techs can help you with? Give us a call 704-684-5339.