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Changing Air Filters: The Simplest, Yet Most Important Job in HVAC

I know what you're thinking. "Filters...Really?" YES, REALLY!

The air filter is the barrier between you and your system, and vice versa. This means that it not only removes bacteria, dust and other microscopic nuisances from the air you breathe, but also protects your system from "breathing" them as well. You need clean air to breathe, but so does your system! First, lets understand the placement of the air filter and why it's important.

In HVAC applications, typically your air filter will be located in the return side of your system. There is a neat little slot it fits into and you will see a coil on one side. On your filter there will always be an "airflow arrow" pointing in the direction that the arrow should face. That arrow always goes toward the coil. The reason for this is that in the correct position, your system will pull max airflow across the coil, and a minimal amount of debris (as it is caught in the correct side of the filter).

Another important thing to note, is that there are many filter options available depending on your system. ASHRAE suggests using the highest MERV rating possible, however the higher the MERV rating, the lower the airflow through the filter, so we need to make sure its also rated for that particular system. In the residential field the highest MERV rating is MERV 13, however not every system will be able to accommodate this rating either in space, or airflow so you will need to choose a lower rated filter. All systems have a specified filter size that is recommended for use in that application and its important to follow manufacturer instruction when choosing a filter.

As you can imagine, air filters become clogged and dirty quickly as our first line of defense against air debris, so it's necessary to change them often! In most HVAC applications it's recommended that they be changed quarterly (every 3 months) either by the homeowner, a maintenance tech, or an HVAC tech. Failure to change them often enough causes your system to not run properly, causing heating/cooling issues, breathing problems, and even illness in some cases.

In summary, we need to filter our air to protect our lungs, AND our HVAC systems. We need to make sure our filter is the correct size and shape, and is facing the correct way for max air flow and filtration. We must make sure that our filter is the HIGHEST possible MERV rating for said system, without being too high, and we need to change our air filters every 3 months to ensure our system (and lungs) are working efficiently!

As Always,

Be Kind HVAChicks~ That's What Sets Us Apart!


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