My HVAC system is around 15 years old and I have a washable air filter. The tech who looked at it last told me to clean the filter out and run water through it once a month.

He told me to let the filter dry for 3 hours before replacing it. I had a different tech tell me, however, to shake the water out of the filter and put it right back in.

So that leaves me with two questions.

Do I let the filter dry for 3 hours or shake it and put it back? Is it safe to let my HVAC run for 3 hours without a filter?

Thanks for all help in advance!

  • 1
    Been in the trades for years Any thing that last that long, is a blessing. I would buy a new filter. – user101687 May 31 '19 at 0:21

Depending on the filter media a soak and squeeze it out then put it back in some fiber filters you need to have 2 , pull the dirty one and put the clean one in now after cleaning in a week the fibers will be clean and dry , but if put in wet it can cause enough back pressure to rip the filter and on 1 or 2 models damage the blower motor. Some reusable filters do last for many years if regularly cleaned with non chlorinated water, I tell folks just put a few drops of jet dry in a gallon of distilled water this breaks the surface tension of the water and helps to remove any “dust” without harmful chemicals ,, heck you have it in your dishwasher to prevent spots, I have done this for years it helps to clean the 2 types of filters I have experience with. No comment for the - I give a +

| improve this answer | |

If you put it back in while still wet, it will release moisture into the air stream. If you are in heating mode that is going into the heat exchanger of your heater. Too much moisture hitting the hot plates in the heater could cause them to corrode or eventually crack.

It wouldn't do much to your AC however, because they are designed to remove moisture anyway, which is possibly what that technician was thinking. So if you were cleaning it in the summer, I wouldn't worry about drying it but in the winter, I would.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.