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

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

4 tons central AC or heat pump, about 43,900 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.7 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 547 square feet in this climate. For a single room, size by the room: 21.9 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Redding Airport (4.5 mi away). Jul is the hottest month, averaging a high of 99.9°F and a low of 67°F, with about 106 days a year at 90°F or more. That gives a design temperature of 107°F against 75°F inside.

What it costs to run

About 2,823 kWh a year at SEER2 14.3, or roughly $920 at California's average residential rate of 32.58¢ per kWh. Cooling runs 6 months of the year here.

What drives the load in Anderson

Of the 43,900 BTU/hr, 23,040 comes through walls, roof and windows on a 107°F afternoon (52%), 13,000 is sun on the house (30%), 2,120 is four people and their appliances, and 5,700 is moisture the coil has to wring out of Anderson'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 38,160 BTU/hr before the moisture allowance.

Other house sizes in Anderson

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,300 BTU/hr; a 350 sq ft living room needs about 7,700 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 13,100 BTU/hr.

Month by month in Anderson

Jul alone uses 28% of the year's cooling energy. The unit runs the equivalent of 920 hours a year at full output.

Anderson against nearby cities

Of 376 California cities here, Anderson has the 32nd highest cooling load. The range runs from Corte Madera at 15,700 BTU/hr to Palm Desert at 59,000.

Where Anderson's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Redding Airport, 4.5 miles from the center of Anderson at 501 ft above sea level. That is close enough that the station's summers are Anderson's summers.

1 other city uses the same station and get the same climate inputs. The closest to Anderson: Redding (9 mi away, 5.3 mi from the station). Anderson sits closer to the station than any of them, so its numbers are the best measured of the group.

The sun over Anderson in late July

At 40.45°N, the noon sun on 21 July stands 70.0° above the horizon over Anderson 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.

11,171 people live in Anderson, the 360th largest of the 376 California cities sized on this site. Coordinates used: 40.4498, -122.2951.

Anderson AC sizing questions