HVAC Filters – If You Haven’t Been Changing Them Monthly, Do It Now!

We’ve made it to the middle of the heating season here in Atlanta, and it’s as important as ever to make sure you’re keeping up with proper HVAC maintenance.

If you read Smiley’s blog often, you probably already know that the single most important heating maintenance measure you should be taking is to replace your HVAC unit’s air filter once a month. Dirty filters impair your system’s performance and can reduce energy efficiency by 10% or more, so it’s imperative to keep fresh filters in your heating system throughout the winter.

Choosing the Right Replacement HVAC Filter

HVAC filters are easy to find at any neighborhood hardware or home improvement store, and are available in many sizes and ratings. The most important measure of a filter’s effectiveness is its Minimum Efficiency Reporting Value (MERV) – less efficient filters have lower MERV ratings than more efficient filters.

Here are the main types of HVAC filters available, and some information about each to help you find the best option for your system.

Fiberglass Filters

Fiberglass filters are one of the cheapest filtration options, and are also the least effective. Fiberglass filters typically have a MERV rating between 1 and 4 and only remove less than 10% of pollutants from the air. These thin filters are the least expensive option but aren’t recommended as they do little to improve or protect indoor air quality.

Polyester & Pleated Filters

Filters made from polyester and pleated to increase the surface area air needs to pass through are more effective than plain fiberglass filters, and can remove up to 45% of the pollutants in your home. These filters typically have a MERV rating between 8 and 13. Polyester and pleated filters are usually the best value for the average homeowner.

Washable Air Filters

Washable air filters sound like a great idea on paper – instead of buying disposable filters and swapping them out for the old ones every month, a washable air filter can be washed and reused over and over.

In reality, washable air filters are among the worst options you can find. They typically have a low MERV rating of between 1 and 4 and require extensive cleaning and maintenance, and have a tendency to collect bacteria and fungus – the last thing you want sitting in your HVAC ducts! Avoid using washable air filters.

High-efficiency Filters

The highest efficiency HVAC filters are MERV rated between 14 and 16 and can remove up to 85% of the contaminants from a home or building space. Typically made from pleated filter paper or synthetic fibers with only tiny spaces for air to pass between, these filters are highly effective at trapping small particles of dust, mold, pollen, smoke, and other irritants. These types of filters are not terribly practical for residential use, however, and are normally found in hospitals or “clean rooms” like laboratories.

A Few Final Thoughts

As you look for replacement filters, remember that the best filter for your HVAC system may not be the one with the highest MERV rating – higher levels of filtration can also mean higher air pressures are needed to keep air flowing through your system, which can increase system load and decrease energy efficiency or even lead to breakdowns. The best filter will be one that provides reasonable filtration while allowing your system to operate at maximum efficiency.

If you any questions about your HVAC system’s filters, or need advice about replacing them, give us a call today – we’re always happy to help direct Atlanta homeowners toward the best heating solutions for their situation.