What size AC for Hesperia, CA? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 42,200 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.5 tons. This is one of the climates the chart was written for.

If a contractor quotes you more than 4 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 568 square feet in this climate. For a single room, size by the room: 21.1 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Hesperia 2e (3.2 mi away). Aug is the hottest month, averaging a high of 97°F and a low of 65°F, with about 108 days a year at 90°F or more. That gives a design temperature of 105°F against 75°F inside.

What it costs to run

About 2,674 kWh a year at SEER2 14.3, or roughly $871 at California's average residential rate of 32.58¢ per kWh. Cooling runs 6 months of the year here.

What drives the load in Hesperia

Of the 42,200 BTU/hr, 21,600 comes through walls, roof and windows on a 105°F afternoon (51%), 13,000 is sun on the house (31%), 2,120 is four people and their appliances, and 5,500 is moisture the coil has to wring out of Hesperia'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 36,720 BTU/hr before the moisture allowance.

Other house sizes in Hesperia

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,200 BTU/hr; a 350 sq ft living room needs about 7,400 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,700 BTU/hr.

Month by month in Hesperia

Aug alone uses 26% of the year's cooling energy. The unit runs the equivalent of 905 hours a year at full output.

Hesperia against nearby cities

Of 376 California cities here, Hesperia has the 41st highest cooling load. The range runs from Corte Madera at 15,700 BTU/hr to Palm Desert at 59,000.

Where Hesperia's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Hesperia 2e, 3.2 miles from the center of Hesperia at 3,055 ft above sea level. That is close enough that the station's summers are Hesperia's summers.

No other city in this set uses Hesperia 2e, so this sizing is Hesperia's alone.

The sun over Hesperia in late July

At 34.40°N, the noon sun on 21 July stands 76.0° above the horizon over Hesperia and the day runs 13 h 58 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.

101,836 people live in Hesperia, the 74th largest of the 376 California cities sized on this site. Coordinates used: 34.3970, -117.3152.

Hesperia AC sizing questions