Many HVAC systems come with an air filter. The point of this is to trap any contaminants, such as dust and dirt. This is so the air is safe to breathe. One question that many HVAC professionals hear is “Are all air filters the same?” No, air filters may share the same purpose, but they are not the same.

The Types of Air Filters

There are a few types of air filters that have two types of classifications: type and MERV rating. MERV is short for “minimum efficiency reporting value”. It shows an air filter’s ability to trap pollutants. The rating can range from one to 20. A high rating signifies greater performance.

Here is a list of the most common air filters and their purposes.

Disposable Air Filters

Disposable filters are the least expensive type of filter. They use flat fiberglass or a polyester mesh designed to remove particles from the air. Disposable air filters have a rating between one to four. These protect the HVAC unit.

Reusable Filters

Like disposable air filters, reusable HVAC filters use either polyester mesh or fiberglass. They are also given a rating of one to four. These filters are more for protecting the unit. What sets them apart from disposable filters is that you can wash and reuse them.

Electrostatic Air Filters

Electrostatic air filters are different than the two listed above. They use an electric charge to trap particles as they go through the filter. Electrostatic air filters perform much better than reusable and disposable ones. These specialized air filters have an average MERV rating of 15. You should know that they aren’t compatible with all HVAC units.

HEPA Air Filters

HEPA air filters are the most efficient and well-known air filters to date. These filters have an average MERV rating of 17 to a full 20. These filters can remove up 99.7 percent of pollutants. There is a slight drawback. To use HEPA air filters to their full ability, your unit needs to exert a large amount of pressure. This makes them restrictive for most heaters and air conditioners. They are also more expensive than other types.

As you can see, air filters may share the same goal, but what they do depends on what type it is. Do you need an air filter? Say no more! Contact Harwich Port Heating and Cooling at (508) 593-9436 and we’ll make sure you’ll be able to enjoy the fresh air!