Need advice on central AC unit(s) (credit, how much)

[rustedteg]

I have a 1 1/2 story house being built and need some advice on the AC. The house is 2400 sf with only a gameroom (340sf) upstairs that open to the 1st floor. The ceiling is 18" all around most of the house. I have a choice to choose between the following options:

1. 1 16 Seers Unit Dual Zone
2. 1 Large and 1 small 14 seers units.

I do not have the specs on each at the moment. I will provide that when I get it.

Thank you in advance!

[skids929]

Having a dedicated compressor and zone will probably work less than one cooling two spaces, but need to consider how many tons each unit is as well..Nice thing about the one running two spaces is less equipment, only one line-set, one condenser etc. Which means less replacement cost down the road too...But, does it effect comfort and efficiency. I would ask the builder what the tonnage of all the units are, and the go from there. Tonnage on the 16 should be highest.. It's very important they are sized right... Also is there a price difference between these two options they give you?

If the one can handle it all, and there is a control up there to turn it of and on I might go that route. But an argument can be made that a dedicated unit for each zone will work more efficiently and may offer a better level of comfort. Lord knows it's important with the intense heat in Texas.

[rustedteg]

Thanks for the reply. I will find out what tonnage they are as soon as I can. The price won't change regardless which option I choose.
I'm leaning toward the 2 units because just incase one go out, we still have the other until the broken one is replaced. But I'm curious if their is a big difference between the 16 seers and 14 seers?

[TX75007]

Depends on the tonnage and the number of stages in each.

I'd get the model numbers, too, and post on here, then we can look up the ratings.

In general, a 16 SEER two stage will be best.

Another option is to buy it yourself and get the tax credit.

[rustedteg]

Here are some info I was able to get
Small unit: Carrier ca16na024 2tons
Large unit: Carrier ca16na048 4tons

16 Seer Unit: 5 tons 16seers 2 stage (That's all I could find out)

More info can be found here: http://www.xpedio.carrier.com/idc/gr...a16na-01pd.pdf

Thank you!

[TX75007]

Will you have air returns in every room?

Where will the returns be located?

How much fresh air will be added to the return?

[nsumner]

The fact that the upstairs gameroom is open to the downstairs, you will have to run both units constantly otherwide the downstairs unit will work harder to cool the upstairs.

16 seer vs 14 makes a pretty big difference. I would upgrade to a 16 seer for both units or negotiate with the builder to make it a standard for you.

Naima