Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 8/29/2017

I have 2500 sf tri level home with 350 sf in basement, 1250, on main floor and 850sq upstairs. What size ac unit ?

Do you have the same question? Follow this Question

1 Answer


Depends on your locale, sun exposure and number of sun-exposed windows, house insulation, how spread-out the house is (i.e. outside wall exposure), type of roof (ventilated or not) and such. i have seen glass-wall houses in the Mojave Desert need a ton per 250 SF, and super-insulated "tight house" with thick-wall modernistic construction with minimal windows getting by on a ton per 1000 SF, and even less in partly in-earth construction - the general average in the US is about 400-500 SF/ton. So - depending on your house constreuction and climate and such, probably about 4-5 ton unit (basements usually don't count if mostly in-ground because the natural ambient temperature is below what the A/C is set for anyway, so they usually naturally cool).

But you need a Heating and A/C contractor experienced in system design (or your Architect's mechanical engineer if using an architect for your project) to run the ACCA design manuals on your system - Manual J to figure the calculated heating/cooling loads, Manual S to size the unit (determine required heating/cooling capapcity as applicable, and required airflow), and Manual D for duct design if using conventional ducted rather than a mini-split unit.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy