Furnace Filter Replacement Guidelines

How often you change your furnace filter will depend on the type of filter you use, and how you operate your furnace. Select the type of filter you use from the list below to find out what you should be doing.

Disposable Filters - Disposable filters should be changed every 6 to 8 weeks. A lot of people try cleaning these filters but they are not really meant to be cleaned and may actually become even less efficient. Disposable filters are not very efficient and provide only a basic amount of air cleaning. If you run your furnace fan continuously, cleaning should be performed every 3 to 4 weeks.

Washable Filters - Washable filters should be cleaned every 6 to 8 weeks for normal use. If you run your furnace fan continuously, wash filters every 3 to 4 weeks. When you wash your filter be sure to inspect it for wear and tear.

Hammock - Hammock filters are not meant to be washed and should be replaced every 8 to 10 weeks. When you purchase a replacement hammock filter it may be a little larger than the metal frame it’s attached to. Install the filter on the frame and then trim off the excess.

Electrostatic Air Cleaner - Electrostatic air cleaners must be cleaned monthly. To clean them first vacuum the nylon media and then rinse the filter with water. Be sure to raise the filter in the opposite direction from the air flow. Electrostatic air cleaners are very difficult to get very clean so as your filter gets older, clean it even more often. When cleaning inspect it for damage and wear and tear.

Electronic Air Cleaner (EAC) - The most important thing to remember about electronic air cleaners is to keep them clean. EACs are very efficient until the cells get dirty and then lose a lot of their efficiency. When cleaning the cells be careful not to break any of the thin wires that run along the outside of the cells. If one of these wires break, the cell current will be broken and will not work. Do not forget to clean the small prescreens as well.

Large Pleated Media Filter - This is the easiest filter to clean. All you have to do is replace the media cartridge semi-annually. Arrange to have your cartridge replaced at the same time as you have your annual heating and cooling maintenance performed.