What size AC for Tooele, UT? 3 tons for 2,000 sq ft

What size AC a 2,000 sq ft house in Tooele needs

3 tons central AC or heat pump, about 35,600 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 18% more than this climate needs. An oversized unit cools the air fast, shuts off before it pulls moisture out, and leaves the house cold and clammy.

If a contractor quotes you more than 3 tons for an average 2,000 sq ft house here, ask to see the Manual J load calculation behind it before you sign. That works out to one ton per 674 square feet in this climate. For a single room, size by the room: 17.8 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Tooele (0.8 mi away). Jul is the hottest month, averaging a high of 91.4°F and a low of 64.1°F, with about 56 days a year at 90°F or more. That gives a design temperature of 97°F against 75°F inside.

What it costs to run

About 1,511 kWh a year at SEER2 14.3, or roughly $199 at Utah's average residential rate of 13.19¢ per kWh. Cooling runs 4 months of the year here.

What drives the load in Tooele

Of the 35,600 BTU/hr, 15,840 comes through walls, roof and windows on a 97°F afternoon (44%), 13,000 is sun on the house (37%), 2,120 is four people and their appliances, and 4,600 is moisture the coil has to wring out of Tooele's summer air (13%).

Heat through the shell is the biggest share here, so insulation and air sealing cut the size you need more than shading would. Sensible heat totals 30,960 BTU/hr before the moisture allowance.

Other house sizes in Tooele

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,700 BTU/hr; a 350 sq ft living room needs about 6,200 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 10,700 BTU/hr.

Month by month in Tooele

Jul alone uses 37% of the year's cooling energy. The unit runs the equivalent of 607 hours a year at full output.

Tooele against nearby cities

Of 67 Utah cities here, Tooele has the 32nd highest cooling load. The range runs from Heber at 30,700 BTU/hr to St. George at 49,200.

Where Tooele's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Tooele, 0.8 miles from the center of Tooele at 4,944 ft above sea level. That is close enough that the station's summers are Tooele's summers.

No other city in this set uses Tooele, so this sizing is Tooele's alone.

The sun over Tooele in late July

At 40.54°N, the noon sun on 21 July stands 69.9° above the horizon over Tooele and the day runs 14 h 28 min from sunrise to sunset. A lower noon sun puts more of the day's heat on east and west walls than on the roof, which is why shading west glass pays off here. Shorter days give the house a longer night to shed the day's heat.

40,919 people live in Tooele, the 24th largest of the 67 Utah cities sized on this site. Coordinates used: 40.5394, -112.3078.

Tooele AC sizing questions