One of the most crucial HVAC maintenance tasks is taking care of the air filter. This is simple; no specials skills or tools are required, and yet people ignore this basic requirement. An HVAC system needs a clean and clear air filter to work efficiently, and a dirty filter can even damage your equipment. In this article, we will take a detailed look at air filters, explain how they work and how to clean them.

How Often Should You Change Your HVAC Air Filters?

It’s a good idea to check your air filters every month, but you may want to do this more frequently if you have pets in your home. Pet hair can circulate through your home just like any other dust or debris, and ultimately it will end up in your air filter. Hair is probably the material that clogs an air filter in the fastest time period. If you have a disposable air filter with a cardboard edge and it is dirty, simply toss it in the garbage and install a new one. Some people try to clean a disposal air filter to save money, but this is not very effective, and it is simply a waste of time. The best 1” pleated high efficiency air filters can last for up to 3 months before replacement, but during high use periods, they should be checked on a monthly basis anyway.

Where is the HVAC Air Filter Located?

This is a hard question to answer because each HVAC system may have a different air filter location. If you can see a removable access door located somewhere in the return air duct near the indoor unit or furnace, this may house the air filter. This could be in a garage, attic, crawl space, basement, or a similar area in your home. If you have an older HVAC system, the air filter could be located in the furnace. Take a look next to the blower motor, and you may see a filter grille installed in the ceiling or wall. If you swing the grill open, you should see the air filter inside. If you still have the owner’s manual for your HVAC system, it should show the air filter location. If you’ve lost the manual put in the manufacturer name and model and you may find a pdf manual online.

How Does an Air Filter Work?

Many people believe that their air filter is designed to clean the air circulating through their homes. This is partially correct, but the real purpose is to prevent dust, debris, and other material from entering the HVAC system. These materials can cause damage to sensitive components leading to an expensive repair bill. Keeping the air filter clear is essential because the HVAC system needs a consistent airflow to work efficiently. If the air filter is clogged, the system will become overworked in an attempt to keep the air moving. This can lead to an equipment failure and even a premature failure leading to total replacement.

Most modern air filters work in a single direction to keep things simple. The air reaches the air filter then it flows through following the arrow symbol printed on the filter. When you install an air filter, it’s important to ensure that the arrow is pointed towards the air handler or furnace. If you have an air filter that doesn’t have a direction arrow take a close look at the air filter. If you can see that one side of the air filter surface is rougher than the other, this will be the side designed to capture dust. So, make sure that the smoother side faces towards your HVAC equipment, and you should be fine. If your not sure, leave the air filter for a couple of weeks, then take a look, and it should be obvious if the dust is being collected correctly.

4 Steps to Clean a Permanent HVAC Air Filter

If you have a permanent plastic air filter, it can be cleaned and replaced each month to maintain the airflow in your home. Here are four simple steps that you can take, but consult your owner’s manual first if you lack confidence.

  1. Turn Off the Thermostat

Make sure that the thermostat is placed in the “Off” position and find your air filter using some of the methods that we discussed above.

  1. Remove and Clean the Air Filter

Carefully remove the air filter, and if you have not done this in a while, you will soon notice how dirty it is. The best way to clean the air filter is to take it outdoors and give it a clean with a garden hose with good water pressure. Don’t use a water pressure that is too high because you may damage the air filter membrane. The filter should be sprayed at both sides, and if it is very dirty, multiple passes may be required to get the surface clean. When you notice that the water is running clear through the air filter, it is clean. If you cannot work outdoors, you can clean the air filter under a tap, but this may take longer. A reasonable alternative is to clean it in the shower using a showerhead with decent water pressure.

  1. Dry the Air Filter

The air filter must be totally dry before you place it back into your HVAC system. Start by shaking off the excess water and set the filter aside to dry naturally. Some people re-insert the air filter if it is a little damp, but it’s better to err on the side of caution.

  1. Install the Air Filter

Once the air filter is dry, slide it back into the rack where you found it and ensure that the direction arrow is orientated correctly, as discussed above. Then you can turn the thermostat to the “On” position, and you’re done. Repeat this procedure at least once per month, and your HVAC system efficiency will improve significantly.

Be aware that some HVAC systems may have multiple air filters, and they may even be different sizes. The air filter must be the correct size detailed in your owner’s manual, or the air can pass around the sides rendering the filter useless.

If you have any problems with your HVAC system, contact a local specialist for expert help and advice today.