What size AC for North Branch, MN? 2 tons for 2,000 sq ft

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

2 tons central AC or heat pump, about 25,700 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 64% 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 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 935 square feet in this climate. For a single room, size by the room: 12.8 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Grantsburg (22.3 mi away). Jul is the hottest month, averaging a high of 82.4°F and a low of 58°F, with about 9 days a year at 90°F or more. That gives a design temperature of 87°F against 75°F inside.

What it costs to run

About 625 kWh a year at SEER2 14.3, or roughly $103 at Minnesota's average residential rate of 16.44¢ per kWh. Cooling runs 3 months of the year here.

What drives the load in North Branch

Of the 25,700 BTU/hr, 8,640 comes through walls, roof and windows on a 87°F afternoon (34%), 13,000 is sun on the house (51%), 2,120 is four people and their appliances, and 1,900 is moisture the coil has to wring out of North Branch's summer air (7%).

Sun is the biggest share here, more than heat through the walls, so shading west windows and a light roof cut the size you need more than extra insulation would. Sensible heat totals 23,760 BTU/hr before the moisture allowance.

Other house sizes in North Branch

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 1,900 BTU/hr; a 350 sq ft living room needs about 4,500 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 7,700 BTU/hr.

Month by month in North Branch

Jul alone uses 37% of the year's cooling energy. The unit runs the equivalent of 348 hours a year at full output.

North Branch against nearby cities

Of 103 Minnesota cities here, North Branch has the 70th highest cooling load. The range runs from Hibbing at 20,200 BTU/hr to Winona at 29,000.

Where North Branch's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Grantsburg, across the line in Wisconsin, 22.3 miles from the center of North Branch at 990 ft above sea level. That is close enough that the station's summers are North Branch's summers.

No other city in this set uses Grantsburg, so this sizing is North Branch's alone.

The sun over North Branch in late July

At 45.51°N, the noon sun on 21 July stands 64.9° above the horizon over North Branch and the day runs 14 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. Long days mean the house keeps gaining heat into the evening, well after the outdoor peak.

12,258 people live in North Branch, the 94th largest of the 103 Minnesota cities sized on this site. Coordinates used: 45.5099, -92.9557.

North Branch AC sizing questions