Unsealed return air ducts costing big $
I was wondering if any HVAC guys would tell me why some installers don’t see the need to seal their supply and return lines. I just came home after seeing my first blower door/infrared camera test. We found the furnace was pulling air out of the floor system, which led straight to the attic via open web floor trusses. The vents in the bedrooms wouldn’t even suck a piece of paper up against them. The poor heat pump was running frantically, drawing in 15 degree fresh outside air, (story-and-a-half, open web floor trusses, no sheathing or air barrier on outside rim truss, fiberglass blown in insulation). As far as I can tell there’s a major gap in the return air lines. The homeowner remembers his 14 can lights above the kitchen counter playing havoc with the HVAC install. Maybe an electrician inadvertently knocked some panning off? Maybe the HVAC sub didn’t care where the air came from? Maybe he didn’t think the homeowner would notice a $900/month heat bill even though he paid $30,000+ for a geothermal unit? Somebody please tell me it was an honest mistake and I’m not surrounded by trades that don’t care.