HVAC thread name change: Help me out with AC tonnage. (bottom of page 1)

The biggest pros of the dual system:

1. Multiple zones = better control of separate spaces
2. Both won't go out at once, leaving you with one that can keep an area comfortable until the other is fixed.
3. When one needs to be replaced, it will be cheaper than replacing a bigger unit, making it easier on the budget.

First get another estimate. I had 2 new units installed 2 years ago and my gap wasn't nearly that high. That was with a 3 ton and a 2 ton unit I believe.

The multiple zones is well worth it. I don't spend time upstairs during the daytime. We pretty much only sleep there. I can kick on the air/heat an hour before bed and have it ready. Then adjust the lower level as I go to bed and not waste electricity.

I replaced a 5 ton unit on a 2000 sq foot single level house and then moved into my current 2300 sq foot 2 story. Electric bill is about 100 a month less with the current house even running a pool filter 12 hours a day.

Note: this is for ~2600SF, fairly open floor, single story, bedrooms on one side, kitchen/dining/entry/laundry on the other.

How cold do you set the thermostat at night? If you like it cold, I would get 2 units. Maybe a 3 ton for living and a 2 ton for the bedrooms.. Get multiple quotes.

Great advice. Carrier user here as well. I have had fantastic luck with them.

Got a few more quotes, don't know what to make of them. Tonnages all over the map.

All requested my plans so they could run calcs. They're sorted by least cost to operate to highest cost to operate. The colored cells are the actual cost of installation. The highest (7 total tons 20 seer) and the lowest (one 5T 16 seer) have almost the same operating cost but the 7/20 is over double the price. Operating cost based on

(((tonnage x 12000)/seer)*avg hours per year)/1000)* (cost per KWH)

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in before "stay away from goodman"

these are from three local companies. i just received one more for Hiel brand. I have two more quote requests outstanding. the three 4T setups are companyA, the two goodman are companyB, and the rest of the ruud are companyC.

Call Doug's.

quote:

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Tonnages all over the map.

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Because the vast majority of a/c guys don't know how to use ASHRAE Manual J. Ask them if you can see their load calculations.

ETA - The only one of the 6 ton guys I would even consider is the one who suggested a dehumidifier. The other guys are setting you up for indoor air quality issues.

Dual is nice. Our house was built in the 60s. The guy I had out servicing a couple years back pointed out to me there used to be a larger air handler and furnace. We currently have a 3.5 or 4 ton downstairs with a couple of old ducts that still blow upstairs. And a 1.5 or 2 ton heat pump upstairs. We’ve liked having two. Leave upstairs off except at night. Since it is kids bedrooms only up there.

That being said, he suggested when I do replace to go with around a 4.5-5 ton unit. It will cool and heat downstairs easier and we can still keep the heat pump as backup for upstairs or on those really hot stretches in the summer to run both at once.