The question at the bottom of this long post is: Who is crazier, Contractor 1 or Contractor 2?
1982 2-story 1750 sq ft house in northwest Austin, TX. Living, master, kitchen on top floor so thermostat is on top floor. Slab, no basement, you just enter the house using stairs... (it's weird, I know).
House is shaded by trees, hillside, and neighboring houses. No windows get very much direct sun -- mostly shaded by trees.
Current A/C: 1985 GE 4-ton SEER 6 and pilot lit gas furnace.
I called 3 different contractors, two that do the city energy audit thing and a third guy who doesn't in case I could only afford HVAC replacement.
About 40 ft of ducting is bad and the insulation is in dire need of revamping (R-30 is the city standard for rebates). They all said this so I'm definitely fixing that stuff.
says that since there's a 4 ton in there and it looks to him that the in-wall duct is set up for that, he recommends a 3.5 ton, even though 3 ton is what the square footage calc should yield (600 sq ft per ton, city recommendations). The reason given is so that the 55 degree air from a 3 ton blower doesn't sit there in the bigger 4-ton size channel heating up.
says that since the house is so well shaded, the first floor is completely covered, thermostat is upstairs, etc. he recommends a 2.5 ton unit. I tell him what Contractor 1 said about air movement and he said he thought the in-wall duct looked to him sized for smaller than a 4-ton. He also thought a larger unit would go on and off all the time.
didn't bring a ladder. So I told him about the duct work and insulation and he said he'd quote me on that and bid a 3.5 and a 2.5 ton system.
Contractor 1 swears by Carrier, Contractor 2 swears by Lennox, but they'll both install most of the major brands. Contractor 3 will install pretty much whatever you want.
My question is: Is Contractor 2 crazy and potentially severely underpowering the system or is Contractor 1 crazy and potentially overpowering the system?
Thanks for ANY help!!!