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

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

3 tons central AC or heat pump, about 35,000 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 20% 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 686 square feet in this climate. For a single room, size by the room: 17.5 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Lodi (1.1 mi away). Jul is the hottest month, averaging a high of 92.4°F and a low of 59.1°F, with about 78 days a year at 90°F or more. That gives a design temperature of 99°F against 75°F inside.

What it costs to run

About 1,694 kWh a year at SEER2 14.3, or roughly $552 at California's average residential rate of 32.58¢ per kWh. Cooling runs 6 months of the year here.

What drives the load in Lodi

Of the 35,000 BTU/hr, 17,280 comes through walls, roof and windows on a 99°F afternoon (49%), 13,000 is sun on the house (37%), 2,120 is four people and their appliances, and 2,600 is moisture the coil has to wring out of Lodi's summer air (7%).

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 32,400 BTU/hr before the moisture allowance.

Other house sizes in Lodi

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,600 BTU/hr; a 350 sq ft living room needs about 6,100 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 10,500 BTU/hr.

Month by month in Lodi

Jul alone uses 26% of the year's cooling energy. The unit runs the equivalent of 692 hours a year at full output.

Lodi against nearby cities

Of 376 California cities here, Lodi has the 140th highest cooling load. The range runs from Corte Madera at 15,700 BTU/hr to Palm Desert at 59,000.

Where Lodi's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Lodi, 1.1 miles from the center of Lodi at 40 ft above sea level. That is close enough that the station's summers are Lodi's summers.

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

The sun over Lodi in late July

At 38.12°N, the noon sun on 21 July stands 72.3° above the horizon over Lodi and the day runs 14 h 16 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.

68,642 people live in Lodi, the 131st largest of the 376 California cities sized on this site. Coordinates used: 38.1216, -121.2908.

Lodi AC sizing questions