Maintaining a clean air filter is an easy and quick way to ensure that your air conditioning, furnace, or central air system runs efficiently. It can also reduce the risk of mold or bacteria growth in your air system while keeping your energy costs down. Check your filter at least once a month when you use it frequently and change it every three months.
How to maintain your air filter
- Change your filter once a month if it is not pleated. If your unit’s filter is non-pleated (has a smooth surface instead of a ridged one), it has less surface area to filter out particles and will become dirty and ineffective sooner. You may prefer non-pleated filters as they often have lower energy costs, but be prepared to change them more often.
- Install a new air filter every three months if you use it frequently. If you use your filter regularly, even if it doesn’t appear dirty, it must be replaced at least once every three months. In the summer months, air conditioners need new filters. The same is true for furnace filters.
- Replace your filter whenever it appears dirty, damp or mouldy. You should replace the filter regardless of how long it has been since you last changed it if it looks dirty, wet or mouldy. If you hold it up to a light, you should be able to see through the air filter. If not, it should be replaced immediately.
How to choose the right air filter
Ask your HVAC installer which filters to use. Ask the technician installing your HVAC unit what type of filter is needed and how it should be installed. Ask the company representative or store to find out what filter you need.
Check a label on your unit that tells you which filter fits. Many air conditioners have labels on the outside of the unit that indicate which type of filter you need to purchase. The labels can be found on any visible part of the unit. The most common sizes of air filters are 16 by 20 (41 cm by 51 cm), 16 x 25 (41cm x 64cm) and 20 x 25 (51cm x 64cm). Always go by the size of the air filters and not the actual measurements. These are smaller than what is stated.
Select a filter that has a minimum MERV of 6. The MERV rating measures how efficiently a filter can remove fine particles. More efficient filtration also means using more electricity, so a higher rating will increase your energy bills. An average rating of 6 for filters is a good compromise that balances affordability and filtration efficiency.
How to install a new air filter
If you have central heating and air conditioning, locate your HVAC unit. You’ll have to locate the main unit if you have central AC. It’s usually located in a closet, basement or another out-of-the-way space. Follow any pipes or ducts in your home until you find the HVAC unit. It will look like a large metal device.
Look for an air filter slot in your unit. On an HVAC unit, this will probably be somewhere between the air handler, a large box where the air is conditioned, and the plenum, another metal box next to the unit itself. The filter slot should be behind the grill facing your house on a window air conditioner.
- The location of the filter opening may vary from unit to unit, but it should look like a long, thin hole with a removable cover. If you can’t find the filter opening on your HVAC unit, try looking for it in the vents that supply air to your rooms. Some systems have filters in the return air vents, although this is usually only the case with systems with two or fewer vents.
Turn your unit off. You”ll want the unit to be off when you change the air filter to avoid damaging the appliance or yourself. This will also prevent dust or particles from entering the unit while removing the filter.
Remove the old filter. The filter should be able to slide out. When removing the filter, be careful, as it could be covered with dirt and dust. If you handle it too roughly, it can come off and cause a mess.
Insert a new air filter. The air filter should slide into the slot easily and without resistance. On the filter’s side, an arrow should indicate the direction the airflow is moving. This arrow should point in the same direction as the old filter towards the unit’s ductwork and blower.
Look for gaps around the filters once they are in place. Remove the new filter and temporarily replace it with the old one if you find any. You may need a replacement if you have the wrong filter size. Your new filter may have been damaged or misshaped. If you find any damage, return it to the shop and get another one.
To check if the unit is still working properly, turn it on. It should run like before or have slightly more air pressure. Call an HVAC technician if you hear or smell something strange or your system doesn’t work.
Keep a note of the date you changed the filter. This will allow you to keep track of the frequency of filter replacements and help you remember the due date for the check. You can make a note on your computer or phone or write it somewhere easy to remember.
