Filter question

[gregtwojeeps]

I have a Luxair horizontal flow condensing gas furnace in my crawlspace that has the filter rack on the return end of the furnace. The return filter box holds one 20" x 25" x 5 in" thick pleated filter snugly. .... The big box stores locally carry the 4 " thick filter in stock, but not the 5 in. thick filter so I have been ordering them from Amazon $$$$$$ .

I know the average furnace in a home with 1000 -2000 sq.ft. usually has just one 20" x 25" x 2" ( or 1") filter in the return box. I wonder why my furnace has this, " hard to get in stock" 5 in. thick filter that is ....a LOT more expensive ? Do I have to keep it this way ? My home is only 1350 sq. ft.

 

[Chris705]

I currently buy the 20x25x4" filters from Home Depot for my 2 yo furnace.....I like that I only have to change that filter once a year (no AC)....should be changed monthly with the 1" thick filters.

I think you could build yourself a wood frame 1" thick as a spacer and you should be fine.... HD two pack of these Merv 8 filters is $40. If you have AC I think you need to replace twice a year.

 

[casetractorfarmer]

Could u just stick a 1 inch filter on the 4 inch and it would work

 

[bonneyman]

I find old electronic filters cells are 5" wide, and when they burn out nobody ever wants to pay the $$$ to replace them. So, I convert them over to 4"pleated filters. Never had a problem.

 

[tomroblee]

The thick pleated filters are designed to filter more of the small particles out of the air. The finer the particles that the filter media is designed to handle, the larger the surface area needs to be.

If someone in your household has asthma and/or is allergic to pollen or ? in the air, you may want to stick with the expensive filters. The furnace should run just fine with a cheaper filter. I suggest that you go to the manufacturer's website and see if filter requirements are listed. The product manual will often specify a MERV (minimum efficiency reporting value) rating. (The air handler is designed to operate within a general range of static pressures. Using the wrong MERV filter may change the static pressure.

For a better description of MERV values, see the attached link:

http://furnacefiltercare.com/performance/merv-ratings/

You may find better filter prices by shopping at a filter supply house and buying in volume. Minimum volume is generally a case. Five inch thick filters will fill a box rather quickly, so I doubt that there are all that many filters in a case.

 

[gregtwojeeps]

I find old electronic filters cells are 5" wide, and when they burn out nobody ever wants to pay the $$$ to replace them. So, I convert them over to 4"pleated filters. Never had a problem.

It appears you have answered my question Bonneyman

It looks like a old EC unit they have removed and the PO just stuck a 5 in. deep pleated filter in it. I will start using the more common 4 in. thick filter and just make a filler to go in behind it to keep it snug, as Chris suggested above. Thanks all