I have a 5 Ton heat pump duel fuel propane unit with an electronic air filter in a new 2300 sq ft house. After four months of running with standard fiberglass filters, I stopped using them when the construction dust diminished.
The two foot by three foot metal return grill sings when the unit runs without the filter. I am wondering if there is adequate return vent size for the job. The actual clear opening size of the return duct that goes through the floor is 14 X 19 inches.
The single return is in a hallway with no other return ducts.
I wish I had known about this web site before, because I would have been a better informed consumer. I would have requested more return air ducts. When the bedrooms are closed off, there is noticeable air pressure resistance when the doors are opened.
Is my return undersized? Would it be something that should be fixed to increase efficiency and longevity of the unit?
I thank you.