I am having my old Carrier 100,000 BTU single stage furnace and a Carrier 3 ton AC replaced and wanted to see if you all thought this sounded about right. I'm not very knowledgeable about heating and cooling so I'm looking for reassurance before making the investment.
Where I live, the average summer temperature is approximately 88 degrees and the average winter temperature is 35 degrees (usually several weeks that are much hotter and much colder... nothing out of the ordinary). My house was built in 1936 and is approximately 1550 square feet. There is no insulation in the walls (except in some areas where I remodeled) and I did upgrade the insulation in the attic. My wife and I have a young daughter and are planning to stay in this house for a long time.
As you can imagine the upstairs is hard to keep cool. The two bedrooms each have a supply and return, but the supplies are small. The ducts in the basement heading to the 2nd floor are rectangular (approx. 4 X 12).
I have received several bids --there is disagreement on 3 ton or 2.5 ton on the AC and some suggested a two stage furnace thinking that the VS might not be strong enough to move air on the second floor because of the small ducts?
Here are the suggestions:
•Trane XV 90 (80,000 BTU) with a Trane XL13i (2.5 ton) w/ matching coil
•Trane XL 90 (80,000 BTU) with a Trane XLi14 (3 ton)
•Trane XL 90 (80,000 BTU) with a Trane XR 12 (2.5 ton) w/matching coil
•Lennox G61 (70,000 BTU) with a Lennox HS 26 (3 ton) w/ matching coil
Thanks for your input or suggestions regarding the AC sizing or models (including r22 or r410a) and comparisons with the Lennox. Am I missing anything?
Again, any thoughts are much appreciated.