I can't find the right air filter size anywhere
I just moved into a house and it has 2 electric heat pumps and 2 air movers - I guess that's what they are. I assumed they were backup furnaces, but I don't really understand after looking at the manual http://www.tappan.net/Literature/514b.pdf
This is my first time having heat pumps in a house.
Anyway, the current filters are size 19.75 x 22 x 5.25
I can't find that size anywhere locally or online. Is it OK to just use a 20x22x4 or 19x22x4, or does anyone know where I can order these filters from?
Thanks in advance.