I met with my HVAC contractor today to review some questions I had for him (my builder was not there). First, I asked him to bring copies of the Manual J, S and D calculations. He didn't have any...he did them "by hand", so he had nothing to show me. I'll be bringing this up with my builder...
Two questions (thanks in advance for any input on these):
1. I have wild heat above my garage, below a bathroom. A qualified friend reccomended that I make sure there is a return in there, or it's useless (like blowing air into a pop bottle). When I asked my HVAC contractor if he was going to put in a return he said 'No, it would just pull insulation back into the furnace.' Should I insist on the return?
2. My friend also did some calculations based on the first floor square footage, the number of returns and supplies, duct size and equipment size. He said that I'm going to be about 400 CFM short on returns for the first floor. When I asked the HVAC contractor about this, he said that since I am using High-Eff furnace with a direct vent, that bringing in the air from outside makes up for that lack of returns. Is that valid?
Thanks in advance!
Rob (Aurora, IL)