Air Conditioning • Energy Audits

What Kind of Air Filter Should I Use?

What Kind of Air Filter Should I Use?
8
Dec

During our last blog we covered how of often you should change your filter. Now let’s talk about what kind of air filter you should be using!

First, before we begin, let’s clarify that the following suggestions are for the average person.

People with significant respiratory issues, allergies or other chronic medical conditions should consult their doctor or an industrial hygienist if they have significant health concerns about the indoor air quality of their home.

With that said, contrary to popular belief and the brilliant marketing from filter manufactures the air filter in your air conditioning system is there for one purpose and one purpose only; to protect the indoor coil from getting dirty. That’s it.

The “filter rack” or space where your filter goes was never meant to purify the air of your home!

But I see advertisements for high efficiency air filters endorsed by celebrities on TV?

Most of the high efficiency filters on the market today significantly degrade the efficiency and capacity of your AC system. Studies show that these filters can rob as much as 40% of your AC systems efficiency! The celebrity endorser and filter manufacture are not concerned about your utility bill though! They do not care if your home cools poorly because of their product or about mechanical breakdowns that can happen from these “high efficiency filters” They just want to sell expensive filters at greater profit margins!

Why are these filters bad?

As you know, AC systems have blower motors in them that circulate air through your home. These motors and their accompanying components (wheel and housing) are sized to move a certain amount of air. These motors are also sized to overcome a predetermined amount of resistance to that air moving through the system. This resistance comes from the air having to pass through air grills, air ducts and the air filter. In the industry, this resistance is known as “static pressure” or “pressure drop’ and is anticipated by the equipment manufacture to fall below a certain threshold. If the resistance is above that threshold, the ability of the system to properly circulate the air is greatly diminished. When the air circulating is diminished, so is the capacity and efficiency of the AC system. This leads to longer run times, poor cooling and today’s electronic blower motors are prone to breakdowns due to this excessive resistance.

Keeping the air flowing freely through your AC system is critical to its operation. What these filter manufactures are not telling you is that the $20 filter you bought at the hardware store is actually so restrictive it mimics the same resistance as an entire duct system, in just that little filter!

So, what kind of air filter should I use?

We have great news for you. The answer is the cheap one!

We know, how often does someone suggest you spend less money? But it’s true. The cheap fiberglass filters are the least restrictive on the market and therefore impact your efficiency and capacity the least. This style of filter will help your home stay cool during the hot summer days and when combined with an AC maintenance program that includes routine cleaning (as they should) your AC equipment will stay clean, your home cool and your power bill as reasonable as possible.

For those who are concerned about foot traffic from children or excessive amounts of pet hair, you could use as a basic pleated filter as well. Just try to find one that is not restrictive. Typically the more expensive the filter the more restrictive it is and a basic $4.00 pleated filter will be more than adequate even in these situations.

If you have questions about your filter, feel free to call our office at 941-378-2080 and we would be glad to help!