I live in MA, have (excluding basement) 1800 Sq Ft to cool, and own an 18 yr 4-ton YOrk system (air-handler in attic) that needs to be replaced. I am considering a 4-ton Bryant Evolution with 2 speed compressor.

here's the problem, we're using our 600 sq ft. basement more, and it now has a non-trivial heat-load because of the 3 PCs in it. My solution was to put a 8-10K BTU Window A/C in the basement window, but the guy replacing my Central A/C says that I should just upsize the unit by 1/2 ton and feed the basement fromt the central system. He proposes running a feed and return sufficient for 300 cfm, and says this will save electricity.

My concerns are this:

1) at one end of the basement is a 10' wide closet with the sliding doors removed that now serves as an 'alcove' for one of the PCs. THe only place to run feeds to the basement is such that they terminate in the ceiling of the closet (the rest of the basement is under a living/dining room that has a cathedral ceiling). So will the cooling really be effective when piped to/from the basement at one end (and in an alcove) like this?

2) The return from the basement will be rather long (20') - will it really 'suck' much cooling, or will the air handler mostly suck from the returns that have 6' or so (most of them). the contractor claims he can balance the system to overcome this, but that sounds tricky and perhaps hard to maintain.

3) My kids will be out of the house in a few years, and it's possible the basement will get less use, and eventually have fewer computers. I'm -assuming- that the advantage of a 2-speed compressor is that when my heat load drops, the system throttles back appropriately, so there's no risk in oversizing the system. But I suspect it's not that simple?

4) Then there's the issue that the central system will be cooling the basement 24/7, while a window AC would be used only when the basement is in use (weekday afternoons and some weekends). Maybe the window unit will use less electricity?

Not sure whether I'm buildinga kludge tower here (or whether the window A/C is the kludge)

all thoughts appreciated, thanks!


ps - maybe the basement should be a separate zone? - how would you get enough air down there?

[Edited by jeffw_00 on 08-26-2005 at 09:48 AM]