When I think of it which seems to be every six months. I'll try to do better, sorry.

We have 1 very thick filter. We change it 2x a year ..before heat goes on and before AC comes on.

Every 3 months. 2 filters, one up and one down.

Anonymous wrote:What does the manufacturer suggest for your furnace make and model? This isn’t a crowd source question.

It has more to do with the filter and air quality inside the house. The only way to know for sure is to check the pressure drop, which is easy to do. I change my 1" thick filter every other month. A 4" filter will last a lot longer before the resistance gets too high.

Anonymous wrote:What does the manufacturer suggest for your furnace make and model? This isn’t a crowd source question.

This - ish. Systems can be set up to use different filters, so the recommendation would also be tied to the filter type. For example, we have 2 of the same systems and each use different filters with different replacement recommendations. We at least follow those, but more frequently than recommended is OK too. Most of the 1" thick filters are supposed to be quarterly. We have a 4" thick that is 6 months. I also changed more frequently with pets - esp with high MERV rating (think that the smaller sized holes clog more easily and the fans have more difficultly circulating air if the filter isn't allowing proper air flow).

Some vents can accommodate filters - usually the black thin filters that are primarily for larger dust particles. We had those one each vent (intake and out) at one point and it was super annoying to change them. Those were secondary to the main HVAC filter and we just changed them when it looked like it needed to be done.

My system has 4 filters. The two on our 2nd story are ceiling mounted, but it's just a step ladder I use. Takes maybe 4 minutes total. The ones in the 1st floor and basement are wall mounted and even easier.

We have 4 filters because we have 1 basement gas furnace, 1 1st floor gas furnace, and 1 electric HVAC for our 2nd story. Ours is just a normal 5 bedroom sfh and nearly all have 2 separate units. We have a dedicated inlaw suite in our basement so when we finished our basement we gave it it's own system to make it very comfortable.

It takes you an hour to do 5 filters? Are you an invalid?

Monthly.

Anonymous wrote:What does the manufacturer suggest for your furnace make and model? This isn’t a crowd source question.

They say 3-6 months, varying based on if you have pets, how dusty it is, if you're recently painted or done renovations, etc.

Anonymous wrote:Why would any system require 5 different filters? Each filter has different MERV values?

Our house has 4 systems, 2 heat pump, 2 gas. One of the systems has 2 filters, one on each floor it covers, on the return vents.

Our HVAC company has a maintenance program. They come every 6 months to change filters, check the HVAC and water heater, check UV lights etc. If we see dust around the house then we also buy and change the filters more frequently. The company will then leave the new filters with us.

No pets, no smoking, no shoes indoors and regular professionally cleaned home.

What does the manufacturer suggest for your furnace make and model? This isn’t a crowd source question.

Every 1.5 months.

Every 2.5 months.

Small 3-level townhouse, one on each floor.