What size AC for Eagan, MN? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 28,200 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 49% 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 2.5 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 853 square feet in this climate. For a single room, size by the room: 14.1 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Minneapolis-St. Paul International Airport (5.9 mi away). Jul is the hottest month, averaging a high of 83.4°F and a low of 65.3°F, with about 13 days a year at 90°F or more. That gives a design temperature of 88°F against 75°F inside.

What it costs to run

About 1,153 kWh a year at SEER2 14.3, or roughly $190 at Minnesota's average residential rate of 16.44¢ per kWh. Cooling runs 4 months of the year here.

What drives the load in Eagan

Of the 28,200 BTU/hr, 9,360 comes through walls, roof and windows on a 88°F afternoon (33%), 13,000 is sun on the house (46%), 2,120 is four people and their appliances, and 3,700 is moisture the coil has to wring out of Eagan's summer air (13%).

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 24,480 BTU/hr before the moisture allowance.

Other house sizes in Eagan

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,100 BTU/hr; a 350 sq ft living room needs about 4,900 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 8,500 BTU/hr.

Month by month in Eagan

Jul alone uses 35% of the year's cooling energy. The unit runs the equivalent of 586 hours a year at full output.

Eagan against nearby cities

Of 103 Minnesota cities here, Eagan has the 5th highest cooling load. The range runs from Hibbing at 20,200 BTU/hr to Winona at 29,000.

Where Eagan's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Minneapolis-St. Paul International Airport, 5.9 miles from the center of Eagan at 835 ft above sea level. That is close enough that the station's summers are Eagan's summers.

10 other cities use the same station and get the same climate inputs. The closest to Eagan: Mendota Heights (5 mi away, 4.8 mi from the station), Apple Valley (5 mi away, 9.8 mi from the station), Rosemount (7 mi away, 12.5 mi from the station), Burnsville (7 mi away, 8.7 mi from the station), Richfield (7 mi away, 2.6 mi from the station). Eagan is farther from the station than 4 of them.

The sun over Eagan in late July

At 44.82°N, the noon sun on 21 July stands 65.6° above the horizon over Eagan and the day runs 14 h 53 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.

67,240 people live in Eagan, the 13th largest of the 103 Minnesota cities sized on this site. Coordinates used: 44.8152, -93.1628.

Eagan AC sizing questions