I recently purchased a new Carrier HVAC system and had it installed. Everything went fine. The only hitch was that I asked them to put in a 1″ filter box rather than a 4″ box. Something got screwed up and the installers came out with a 4″ filter box and said that to do a 1″ box, the install would have to be rescheduled. I did some quick math, looked up the filter prices and figured I could work with 4″ filters.
Fast forward 6 months, when I go to put in my first replacement filter. I learn that the filter box isn’t the standard size. It is labeled 16x25x4 but the actual size is 15 15/16 x 14 7/8. The standard size for a 16x25x4 filter is 15 1/2 x 24 1/2. I checked 8 different high volume filter resellers and confirmed that the most common size for a 16x25x4 filters is actually 15 1/2 x 24 1/2. I found that 90% of filters were that size. The size I have is a “Honeywell” size, and shows up less than 5% in online listings. It also costs 3x as much. Again, I don’t have a Honeywell system but a Carrier system.
I also noticed that the original Honeywell filter doesn’t seem to fit correctly against the filter box door (see photo). The door to the filter box has a foam gasket along the sides to prevent air seeping around the filter. But the foam strips are 5 inches apart, while the Honeywell filter is only 4 3/8 wide. That means the foam doesn’t actually touch the filter along the vertical door edge. The metal of the door doesn’t touch the end of the filter so there is a gap of 1/4″ where air simply goes around the filter inside the door.
So in mid July I sent three questions to my vendor, Nugent and Sons in Sterling, VA:
- Why are we using a non-standard size filter box?
- How do I get this box to take a standard size filter?
- Why is there a gap between the original filter and the filter box door?
I was told the questions would be passed along to the ‘install team’. I sent the same questions again in late July. With no response I called their office and was asked to resend the information. I sent it twice (so far) in early August.
Maybe seeing this post will encourage a response?