I need to change my furnace’s air filters, where do I begin?
Changing your disposable air filters is easy to do and should be done every 1-3 months. First, you want to make sure you have the correct size. To determine which size you will need, read the outside of the old filter to see if it is listed. If you can’t find a part number or the dimensions, use a tape measure to determine the length, width, and thickness of the filter. Keep in mind that filter sizes are typically rounded up. This means that a manufacturer might print 20″ x 25″ x 1″ on a filter, but in actuality the filter measures 19 1/2″ x 24 1/2″ x 7/8”. Avoid jamming or bending incorrect size filters into your furnace, it not only impacts the effectiveness of filter itself but can allow dirt and debris into your furnace which could cause costly repairs. Keep in mind, the make, model number or serial number of your furnace, air conditioning system, or air handler does NOT provide much useful information on the appropriate replacement filter.
Now that I have a new furnace filter, how do I change it?
Before changing your filter, you should turn the power OFF to the furnace or air handler. When an air filter is changed dust can be dislodged. If your system’s fan is operating, all that debris can be sucked directly into your HVAC system. Most filters are made in such a way that they can only be easily inserted one way into their slot or air cleaner cabinet. Often, a rigid scrim or wire mesh is on the downstream side of the filter to give the filter the strength and rigidity it needs to do its job properly. The downstream side of the filter is the last surface the air touches and should face the blower of your HVAC system. There should be an air flow arrow on your air filter that will show you which direction the filter should be inserted.