New build AC help! (Howe: sales, new house, living in)

[Prospect85]

Let me start by saying hi as this is my first post to this forum! And now on to the main course.....

So my wife and I are building our first home and after living in a small one story with plenty of A/C problems. The new house is 2520 sq ft. Two story. Only thing upstairs would be a small media room and a small game room. What we're trying to figure out is if its worth it to upgrade from a single 14 seer 4 ton unit to a single 16 seer 5 ton unit. Another option could be to have one of each unit one being 3 ton and one being 5 ton. Is this over kill? Any thoughts? Concerns?

[ChristieP]

Two units is really the best way to go. That way, you can have the upstairs on one, and the downstairs on another, and set the thermostats differently.

[Barefoot Daisy]

Two units, absolutely .. you can keep the upstairs set back and make it comfortable only when you're going to be up there .. it will save you a LOT of money, and keep your downstairs much more comfortable. Programmable thermostats are the only way to go, and learn to use them!

Congratulations on your new home. May you enjoy it for many years!

[Restrain]

We have 2200 SF but is a long rambler. We zoned the home, much better control and functionality.

However, you can do a single large unit and install a thermostatically controlled damper for the single upstairs room. Overall, one unit will be less cost. As you are building, have the AC people put manual dampers on the duct system. Lets you balance the load and airflow,through the system, improving efficiency.

[loves2read]

we lived in older home built in 80s that had large game room upstairs as only room--
it was very warm in winter because hot air followed the stairs up -- we finally had a damper installed and closed it during the winter for most part
it was much more difficult to cool however--

I would definitely suggest two units--
and make sure you get them sized appropriately--
I think a 5 ton for the downstairs you would have--with two rooms up--would be too big and would be more inefficient that a smaller properly sized unit...
just having a bigger unit doesn't make it cool better...

Our current home is over 4000 sq ft, two floors, and has 3 units--
1 for main downstairs is 3 T and there are two others--one for upstairs and one for just master bedroom, bath, and study--
so we can close our bedroom off at night and set the main floor to higher temp
of course we don't do that but we should...would be more energy efficient...

ask your quesitons on web site called GardenWeb.com the building a house forum or the HVAC forum...
you might also consider getting radiant barrier decking for roof plywood and consider radiant wrap on walls...
there is small builder in Tarrant county who tried using the plywood decking w/reflective coating on W and S sides of homes he built several years ago and found they were easier to cool than homes w/regular plywood on exterior walls...

[Prospect85]

Wow thanks for the responses! I plan on meeting with the sales rep and hopefully catch the hvac installer while in there! Gonna pic their brains about some info found here!

[loves2read]

Hope you used a realtor so you have someone on your side in negotiations