Hello,

I just bought a house in Northern Virginia. It is a 45 year old full brick construction colonial home, 2 stories of 2800 sq ft and a basement of 1100 finished sq ft. The home currently has full hydro baseboard heating on all three floors with a brand new 3 zone boiler system. For cooling, the home has a 4 ton air conditioning only system with the air exchange in the attic. The AC is single zoned with only one return on the 2nd (top) floor of the house. Only the 1st and second floor of the house is served by the A/C with vents in the ceiling of the 1st and 2nd floors. I know that the condenser unit is a 16 year old 10 SEER unit that is currently working. I do not know how old the air handler and other components are.

I have 2 goals:

1. Bring air conditioning to the basement as part of a complete basement demo and remodel.

2. Upgrade the current air conditioning system with a new and more efficient system.

I am also considering adding a gas fired central furnace to the system.

I had one company walk the house and look at the system. They are coming back with a project manager to get me a formal quote but they already said "Âthis could be about $20,000". Their idea is to put in a complete new system (A/C only) with the new air exchanger in the basement. They will run a 16"x24" chase up to the attic (through current stacked closets) to tie into the existing duct work for the first and second floors. They will put in new duct work (there is none now) for the basement and another air return in the 1st floor and the basement. They say the air exchanger should go in the basement because the attic access is too small to get equipment in and out without disassembling it. I am 6'2" and 240lbs and I fit through it fine so I am surprised to hear it is too small. I think there idea is too complex and way too expensive.

My idea is to replace the existing units and leave them in the existing locations. I would then install a second smaller (1.5 ton?) unit for the basement. If needed I would add an air return for the 1st floor.

My questions for the group are:

1. The option recommended by the installer seem too expensive. Is it?

2. What option makes more sense mine or the installers?

3. I think their option should cost no more then $10K to $12K and my option should cost no more than $6K to $8K. Am I estimating too low?

4. What is the "sweet spot" in terms of price and performance for modern A/C systems? I am looking at Trane XR and XL systems with 4TFE or 4TEE air handlers.

5. Should I consider adding a gas furnace (as backup to the baseboard radiant hydro heat) to the system while I am doing everything else?

Thanks.