Need to cool two areas of my house. The main downstairs area is 2200 sq ft, and the upstairs is 1000 sq ft.

The first contractor thinks that it is better to install two separate systems because it can be a challenge to balance zones properly with add-on rooms. His suggestion is a 5 ton and a 2 ton system.

A second contractor says that two zones supplied by a one 5 ton system is fine (south side is mostly windows, this is in California so we only run the A/C about 20 days a year).

Also debating between a 14 seer (single stage) or a 16 seer (two stage compressor) system.

Last question: is it okay to place the filters at the air returns instead of at the furnace?

Thanks for any advice!

((The first contractor thinks that it is better to install two separate systems because it can be a challenge to balance zones properly with add-on rooms. His suggestion is a 5 ton and a 2 ton system.))

Two systems are nice I have 3 here BUT I would have him recheck his calculations they seem way to big for me. 5and a 2 will run away with that house and it will be uncomfortable since much of the humidity will be left in the air because of the units short run time.

If you only run the A/C 20 days a year it must not really get that hot so you may consider getting a 3 1/2 ton for the 5 and a 1 1/2 ton for the two. These smaller sizes will pull more humidity out of the home for comfort and also a bit cheaper on the utility bill.

14 OR 16. Let your wallet be your guide.

Make sure the company that is going to do the work knows what they are doing. The install is more important that the name brand.

Get a 10 year factory warranty parts and labor not a warranty from the dealer that is selling it to you. Reason is the dealer might go out of business but the factory probably will not unless you buy some real strange brand equipment from a very small manufacturer.

Is this going to be used for heat? If so go with the heat pump version of the A/C system you are installing. Helps kep the utility bills low.

thanks hvac1000.

I am leaning toward the single 5T two-stage system from Trane. Not a heat pump model, but I will look for that option. My sales guys said that the Trane technology is not cutting edge, but actually better because it has been around for a while and is easier to work on than some of the newer technologies -- actually that has me concerned -- like saying that my old comoro is "better" because it is easier to work on and has been around for a lot longer than my Mercedes.

Is there a way to calculate the energy savings of a 16 over a 14 if you assume moderate load and 20 days x 10 hours = 200 hours a year? The cost for the 16 compressor is around $5,000 ($600 more than the 14). Perhaps this is overkill for only 20 hot days a year?

Will the Trane two stage system really last longer than most contractor grade systems?

Thanks!

The sales guys that are talking to you should have a complete HVAC sales calculator program that will be able to do those 14 to 16 SEER savings figures for you.

If you are only going to need the equipment for 20 days out of the year I would probably just get the cheapest system . That is not much usage and at 200 hours per year the system should last forever.

The name brand is not as important as the professional install.