How often do you need to clean your permanent air filter that is on your furnace in your house? I know you are supposed to replace those throw away filters every month, but every time I check my permanent, it doesn't seem that dirty at all. Last summer, I took it out and spray it down with water real good to clean it...but it didn't seem real dirty then either. How often should you buy a new one?
It all depends on how much surface area the filter has. if it looks like a normal filter (flat), Id clean it every month like a disposable one. If it is an accordian style filter w/ mucho surface area id consult the literature. I own an AprilAire 2200 accordian style filter wich supports disposable and reusable media. The package insert says its good for "one to two years" so i split the difference and set my programmable thermostat to tell me to change/clean it at 18 months. You dont want to change or clean it too often b/c a little dirt makes the system more efficient (per lennox guy), along w/ the fact that replacement media can run you between 30-150 bucks depending on your system. I'm a pimp for high end AC filters. I looked at my ac coils a couple of months ago and you could almost eat off the things. 2200