What size AC for Heber, UT? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 30,700 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 37% 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 2.5 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 782 square feet in this climate. For a single room, size by the room: 15.4 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Heber (4 mi away). Jul is the hottest month, averaging a high of 89.5°F and a low of 49.6°F, with about 39 days a year at 90°F or more. That gives a design temperature of 95°F against 75°F inside.

What it costs to run

About 386 kWh a year at SEER2 14.3, or roughly $51 at Utah's average residential rate of 13.19¢ per kWh. Cooling runs 2 months of the year here.

What drives the load in Heber

Of the 30,700 BTU/hr, 14,400 comes through walls, roof and windows on a 95°F afternoon (47%), 13,000 is sun on the house (42%), 2,120 is four people and their appliances, and 1,200 is moisture the coil has to wring out of Heber's summer air (4%).

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 29,520 BTU/hr before the moisture allowance.

Other house sizes in Heber

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,300 BTU/hr; a 350 sq ft living room needs about 5,400 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 9,200 BTU/hr.

Month by month in Heber

Jul alone uses 49% of the year's cooling energy. The unit runs the equivalent of 180 hours a year at full output.

Heber against nearby cities

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

Where Heber's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Heber, 4 miles from the center of Heber at 5,590 ft above sea level. That is close enough that the station's summers are Heber's summers.

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

The sun over Heber in late July

At 40.54°N, the noon sun on 21 July stands 69.9° above the horizon over Heber 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.

19,042 people live in Heber, the 49th largest of the 67 Utah cities sized on this site. Coordinates used: 40.5417, -111.3879.

Heber AC sizing questions