I had posted a few questions here about 3 weeks ago and got a lot of good replies. Thanks a lot.
Now, I have decided to replace my entire AC unit, also the furnace. Considering long term expenses and the federal rebate, this seems to make better sense.
One of the contractor did a load analysis (don't know if its mechanical D or mechanical J). I had to measure all my windows and doors, specify geographical north. He ran the numbers and said that my tonnage requirement is 4.79, which means I am going for a 5 ton unit.
Bunch of more questions;
I have a single unit with zoning for the two floors of the house - there is a thermostat control for each floor.
One contractor is recommending AC model - 2YABC660 ( or is it 2VABC660?) condenser and CNPHP6124ATA (coils) from Carrier. The furnace (and blower motor) is going to be 58PHA110-120 from Carrier as well.
The other contractor is recommending a 4 ton unit with 24ABC648A (condenser), CSPHP6012(coils) from Carrier. The furnace is 58PHA110. The second contractor is recommending that I have to install a bypass duct work as well. He says that when a single zone is blowing, there is not sufficient air flow over the coils and the equipment doesn't function properly. This costs me an additional $.
So, my question is, is it necessary to get this bypass duct work? Further, is there any other load analysis that needs to be done before I make a decision?
Thanks in advance.