What size AC for Roseville, CA? 3 tons for 2,000 sq ft

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

3 tons central AC or heat pump, about 35,800 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 17% 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 671 square feet in this climate. For a single room, size by the room: 17.9 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Sacramento Metro Airport (15.6 mi away). Jul is the hottest month, averaging a high of 93.6°F and a low of 59°F, with about 84 days a year at 90°F or more. That gives a design temperature of 100°F against 75°F inside.

What it costs to run

About 1,669 kWh a year at SEER2 14.3, or roughly $544 at California's average residential rate of 32.58¢ per kWh. Cooling runs 6 months of the year here.

What drives the load in Roseville

Of the 35,800 BTU/hr, 18,000 comes through walls, roof and windows on a 100°F afternoon (50%), 13,000 is sun on the house (36%), 2,120 is four people and their appliances, and 2,700 is moisture the coil has to wring out of Roseville's summer air (8%).

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 33,120 BTU/hr before the moisture allowance.

Other house sizes in Roseville

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 6,300 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 10,700 BTU/hr.

Month by month in Roseville

Jul alone uses 27% of the year's cooling energy. The unit runs the equivalent of 667 hours a year at full output.

Roseville against nearby cities

Of 376 California cities here, Roseville has the 132nd highest cooling load. The range runs from Corte Madera at 15,700 BTU/hr to Palm Desert at 59,000.

Where Roseville's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Sacramento Metro Airport, 15.6 miles from the center of Roseville at 24 ft above sea level. That is close enough that the station's summers are Roseville's summers.

3 other cities use the same station and get the same climate inputs. The closest to Roseville: Lincoln (7 mi away, 20.2 mi from the station), Woodland (24 mi away, 8.6 mi from the station), Davis (27 mi away, 12.6 mi from the station). Roseville is farther from the station than 2 of them.

The sun over Roseville in late July

At 38.77°N, the noon sun on 21 July stands 71.6° above the horizon over Roseville and the day runs 14 h 19 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.

163,304 people live in Roseville, the 32nd largest of the 376 California cities sized on this site. Coordinates used: 38.7703, -121.3196.

Roseville AC sizing questions