will my current a/c unit work for my addition?

Question

i'm adding onto our house. right now, we have a 2.5 ton trane WCH030C100A 13.5 seer unit. it is only 1 yr old. after the addition, the area to be cooled in our house will be 1140 sq. ft. (excluding closets and laundry rm). the main part of the house is block construction, and the addition will be 2x6. we are getting energy efficient windows installed throughout the house, and re-insulating the attic (fiberglass R-30). we live in phoenix, arizona (hot and dry). no flat-roofs, so there is an attic over every room. will our current unit be okay with an addition?

Answer 1

Go online to your units web site and check it out. Don't forget to caulk everything, shade the sunny side of your house and your A/C unit, and all the rest of those things. All I know is you can help your unit out but you can't push it to cool more area than it is expected to. All you do is run it all the time and your a/c will go like crazy. But you live where it is hot so you know that you can add a window unit to extend your unit and you only need to run it when the sun is on that side of the house or you have a crowd in the room. I live where it is hot and humid and everything you do saves $. Little window units are so cheap my sister put one in her kitchen so help out when she cooks rather than crank the a/c in the whole house. You know--2x6 is not a big addition. . .

Answer 2

I have a home in Tempe AZ and just had a 17 SEER 5 ton A/C installed. The compay was a bit concerned the 5 ton would not be enough. Home is 2350 sqft and has high ceilings everywhere so the volume of air and surfaces to cool is much greater than ave 8'ft ceiling home would be. But the system has worked just fine. Very well actually.

I think you will be fine. I just had great new insulated windows put in. WHAT a difference! In the sun behind the glass I can barely feel any heat. Don't forget the tax and srp rebates on windows.

The hot season is over so there is little need to worry until next summer. Then next summer if the AC runs all the time or cannot bring the temp down then you need to have someone check into your options. Add ceiling fans. Circulate hot air out of the attic. etc

I highly recommend the installer who also installs windows for a major department store but for much higher prices - same window different "brand" name. Let me know if you need his number.

Answer 3

I'm not an HVAC installer, but perhaps my situation will help you decide. I have a 3 ton A/C heatpump system for a 1200 sq ft home. Our climate is not as hot, but more humid (high 90s July into Sep. with 100°+ possible Jun into Sep, 50-65% humidity). Hopefully, an HVAC person will answer your question. It is almost impossible to find any HVAC info on the net.

Answer 4

with the additions your making, R-30 in the attic and such, so long as the addition isnt much more then another 200-250 sq foot more then before you shouldnt notice a thing.