Home HVAC question....

[John]

Hello group... Hoping to get some insight to make a good decision...We are shopping for a new home here in Austin TX, and have come to the conclusion the home will be a two story, probably between 2600-3100 sq foot ...Some builders offer two seperate systems, one for up and one for down, and some offer a single "zoned" system..I think they are all using 12seer units..I don't know which way is better, as I have never had a two story home or a two unit home...It would seem to me the single zoned one has benefits of only being one machine to maintain, but also will get more use...Now, the upstairs of the home will not see much use..It will primarily be used for guest visits which don't happen all that often so that area will be set higher most of the time (or lower in the case of heat) I am guessing the single "zoned" unit would be of a larger size than the two seperate ones, would that affect the monthly cost? Also I asked if the unit can be upgraded to a higher seer and they said they can but it really is not necessary due to the home construction, as anything above a 12 jumps way up in cost... Any thoughts on this would be very appriciated...Thanks! John

[Art Begun]

GO for 2. CHeck Consumer Reports. Zoned systems for HVAC are complicated. I assume you are talking forced air system. Also it will always be working suboptimally instead of 2 separate systems each hopefully optimized.

single

construction,

[Joseph Meehan]

One is usually cheaper to buy, but two is better. In some cases two may not be much more expensive as a retrofit.

[TURTLE]

If you have a upper and down stairs in a home, here is the way to think.

2 zones up and down --- 2 seperate units. 2 zones both on same level. --- 1 units .

The cost to operate two zones unit are of very little difference but a great deal better confort level to have.

2 zone cost to maintain --- It cost a little more to change out 2 -- 2.5 tons verses 1 - 5 ton but after bitching for 20 years about up stair being too hot or cold the price difference is a very small price to pay.

TURTLE

[CBHvac]

That chart is very misleading....thats the BEST readings, in a CONTROLLED LAB..

In higher humidity areas, you will find that your savings are not anywhere NEAR what is POTENTIALLY advertised.

I have several customers that have lower bills than some with new 14SEER units with only 12SEER units...its more in the proper sizing for the area, and home than just slapping in a 18SEER unit and thinking, sometimes wrongly, that your bills will magically go down to nothing.

Once you understand the trade offs of the higher SEER stuff, you understand why they are perfect for Southern CA, but not so perfect for a humid climate.