Hi all,

I'd really appreciate any input on some HVAC install proposals for my house. I've only been in this house for a few weeks when the downstairs furnace died. It's an old system, so I've decided to replace instead of repair. Here are some details:

The house is in North Carolina. Winter temperatures get down into the 20s, rarely colder than that. Summer highs can reach low 90s and muggy. My home is a 2500sqft two-story house with separate upstairs and downstairs systems. The house is 20 years old. Windows were recently replaced and are double-pane vinyl. The upstairs HVAC unit was replaced ~7 years ago, seems to run fine, and I am not replacing it. It's a split system Trane XL14i/XL80 installed in the attic with HW VP 8321 thermostat.

The downstairs system that died was original with the house-- 20 yrs old. It is a split system 2-ton Trane Xe1000/Xe78 installed in the crawlspace. I've been told that my downstairs duct work is in good shape and "was done right", so nobody proposed doing anything with it.

Contractor #1 did a Manual J and determined 21600 BTUH AC and 40000 BTUH heating, but he wouldn't leave his calculation printouts so I don't have any of the details. He proposed a matched Trane system consisting of XR16 4TTR6024B1, XV95 TDH2B060A9V3, and 4TXCB032BC3. Total cost including install, new linesets, "digital thermostat" (model unspecified), and tax is $6500.

Contractor #2 only did a visual assessment and proposed two options, one of which is almost exactly the same as above. Option 1 is XB16 4TTB6024A1, XT95 TUH1B040A9H2, and 4NXCB025AC3. Total cost including install, new linesets, tax, and HW VP 8321 tstat is $5700. Option 2 is XR16 4TTR6024B1, XV95 TUH2B060A9V3, and 4TXCB036BC3. Total cost including install, new linesets, tax, and HW VP 8321 is $6300.

Both contractors provide a 2 year labor warranty with their installs. Although Contractor #1 spent more time here doing a complete load calculation, I actually had a more comfortable interaction with Contractor #2 so I've been focusing on his options.

This contractor tells me that the second stage of the furnace will rarely if ever get used in our climate, and he personally thinks that the XV95 isn't really necessary in our region. I don't disagree with that, but I also think the variable-speed blower will be nice for added humidity control and continuous low-speed air circulation. In addition, the lower sound level of the XR16 is also appealing. Although I may not use that furnace second stage, I'm still leaning toward the more expensive option even though the contractor thinks it's not necessary here.

I'd really appreciate any input you guys could provide-- whether anything seems off with these proposals, or if not, whether the XR/XV combo is worth the added price for my situation. Also, when installed horizontally, does TDH* vs. TUH* matter at all? I found it interesting that the two contractors differed in that aspect. Finally, what about the difference in coil size? All of the proposed systems are AHRI-certified matched systems, as far as I can tell.

Thank you!

This post was edited by indovina on Sun, Mar 30, 14 at 12:11