HVAC advice please

[rustydog]

I am in the market for a new residential HVAC system, and I am being told conflicting advice by different contractors and I don't know who to believe.
I have a large brick ranch with a finished walkout basement.
I have one 25 year old gas furnace in the basement, and one central air unit that serves the whole house. I have one thermostat and it is upstairs. I have no trouble maintaining a comfortable temp upstairs all year, the basement stays comfortable in the summer, but is always 10 degrees colder than the upstairs in the winter. There are five ducts in the basement that blow from the drop ceiling down. There are no returns in the basement.
I want to get a new high efficiency system that will keep the whole house comfortable.
Contractor #1 says I need one new system, and he will add returns in the basement which will equalize the temp between upstairs and the basement.
Contractor #2 says I need two furnaces, one for upstairs, and one for basement. He says adding extra returns to the basement with only one unit will make the problem worse.
Contractor #3 says I can make due with one new unit, but he can seperate the duct work between upstairs and the basement, install a seperate blower for each floor, and put a second auxiliary thermostat in the basement which will solve my problem. I don't know which one is giving me good advice. Please help! Thank you.

[t527ed]

contractor #3 is probably talking about a zoning control for basement. without seeing the system that is how i would go.

[rustydog]

I was thinking #3 made sense to me. I'd rather stick with one unit if possible. I think he did mention "zones" How exactly does that work? What happens if I have both my upstairs and basements thermostats set on 72, and it is 72 upstairs, and 65 downstairs, what happens with zones? Does that mean my furnace will run but only blow daownstairs and not upstairs until the thermostat temp is reached?

[t527ed]

Originally posted by rustydog
I was thinking #3 made sense to me. I'd rather stick with one unit if possible. I think he did mention "zones" How exactly does that work? What happens if I have both my upstairs and basements thermostats set on 72, and it is 72 upstairs, and 65 downstairs, what happens with zones? Does that mean my furnace will run but only blow daownstairs and not upstairs until the thermostat temp is reached?



yes

[rustydog]

Ok, that makes sense. Thank you very much for your information.

[coolwhip]

My advice is to drink heavily. ;)

[tmciver]

rustydog: here's a good article we ran in the past on why zoning makes sense for contractors and consumers alike.
I hope this is helpful.
http://www.contractingbusiness.com/25/GlobalSearch/Article/False/6054/Search

[mjk_na]

Originally posted by rustydog
I have no trouble maintaining a comfortable temp upstairs all year, the basement stays comfortable in the summer, but is always 10 degrees colder than the upstairs in the winter.

My opinion is, you don't need a new system. Zoning it with current system should work.

JMO.

[rustydog]

I guess I could do that with my existing system, but my system is 25 years old, and I don't think it is very efficient. My gas and electric bills are high. I struggled with the decision of whether to go ahead and get a high efficiency system now, or to use my existing system until it dies a natural death.

[mjk_na]

Oops. I slipped on the "25 years old" thing. Well, changing it won't harm you :)