We live in Michigan and our 2000 sq. ft. ranch was built in 1987. Our natural gas, forced air furnace is at the north end of our basement so that end of the house (bedrooms) is always warmer than the south end (living room, kitchen). We never run our furnace higher than 68 but we have higher than average gas bills. Similarly, we never run our AC lower than 80 but our electric bill is almost twice that of our neighbors who run their AC at 72. We had insulation added, our duct work taped, and re-caulked our windows. It doesn't seem to have helped.
Our current furnace: Williamson Gasaver, 120000 BTU, 24 years old. This is a 2 stage furnace that was rewired to run at high only. I believe it could be switched back to 2 stage but we'd need a special thermostat.
Our current AC: Bryant, 2.5 ton, up to 13 seer, 15 years old. It struggles to keep the house at 80 when the outside temp is in the 90's.
When we moved in, 8 years ago, we figured we'd soon need to replace the furnace but it just keeps on going. We have $900 remaining of the tax credit so it seems like a good time to consider a new furnace. We've received 3 quotes (Amana, Bryant & Lennox). All three companies recommend a 95+% efficiency furnace so we can use our remaining tax credit. They also recommend 2 stage and variable speed. We were just looking for a new furnace but they all say our AC isn't big enough and recommend we replace it.
OK folks, we'd REALLY appreciate some input:
*Should we keep our current furnace and look into switching it back to a 2 stage furnace?
*Should we forget about the tax credit and get estimates for less expensive furnaces that are lower than 95% efficiency?
*Can a 2 stage and/or variable speed furnace help solve the problem of it being colder at the south end of our house?
*Can a new furnace improve the performance of our current AC?
Thanks in advance!