noisy HVAC -- do I really need ventilation/louvred door?
Recently put an addition on my house. Now that the heating season is here, I'm noticing that the HVAC air handler is noisy. Not "rattle rattle," but the blower. (I think.) Before I call contractor (who has not been very responsive), I really would prefer to get rid of the ugly louvred door on the machine closet. Go w/ a solid door.
Very important: this is an ELECTRIC unit. Not gas.
Anyone aware of a reason I can't have a solid door & no venting? (There are separate return ducts.)
Unit is a Ruud RHSL-HM2417JA. The manufacturer's installation instructions say it's permitted to install in a non-ventilated space. I can't find anything in the Code that says it needs airflow from the house.
Just for clarity: I have 2 large, common air-returns (one on each floor, each serving 500 sq feet). So I don't believe the louvred door is meant to act as a return.
Do I have to call contractor or his HVAC guy on this?
NOTE: only other thing in closet is an electric water heater. Not a tankless heat-pump water heater. Just ordinary electrical.
Thanks for any help.