My question is in two parts:
I think my house has a problem with negative air pressure. When the HVAC system is running (hot or cold), I get drafts from pretty much every single electrical outlet in the house (the windows are closed when this happens). The air is old, stale smelling and I have problems with allergies.
Here's question 1: I know that I'm losing some air in the crawlspace where the ducts are. Should I assume that if I could seal all those leaks I would acheive equilibrium in the living area? Or can you alert me to other factors I should consider?
Question 2 is related to loss of air in the crawlspace: I spent a half a day down there carefully taping every pinhole leak that could be found. The one I can't seal, however, is the biggest. It comes from the air conditioning coiling coil, which was poorly maintained by the previous owners and is rusted out at the bottom. I need to have that cooling unit replaced, but because of my allergies, I would like to have it relocated to the utility room where the furnace is located. My rationale is that it would then be far easier to clean/maintain the cooling unit while eliminating another opportunity for crawlspace air to enter the duct system. Is this the sort of thing a professional should be able to do for me? If so, what sort of precautions should I expect him to take? I don't want to introduce a critical error into the system.
I intend to call a professional, but I'd like to get as educated as I can first. Thanks.