What size AC for Two Rivers, WI? 2 tons for 2,000 sq ft

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

2 tons central AC or heat pump, about 20,200 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 108% 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 1,187 square feet in this climate. For a single room, size by the room: 10.1 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Two Rivers (1 mi away). Aug is the hottest month, averaging a high of 75.8°F and a low of 59.9°F, with about 1 day a year at 90°F or more. That gives a design temperature of 80°F against 75°F inside.

What it costs to run

About 368 kWh a year at SEER2 14.3, or roughly $70 at Wisconsin's average residential rate of 19.05¢ per kWh. Cooling runs 2 months of the year here.

What drives the load in Two Rivers

Of the 20,200 BTU/hr, 3,600 comes through walls, roof and windows on a 80°F afternoon (18%), 13,000 is sun on the house (64%), 2,120 is four people and their appliances, and 1,500 is moisture the coil has to wring out of Two Rivers'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 18,720 BTU/hr before the moisture allowance.

Other house sizes in Two Rivers

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 1,500 BTU/hr; a 350 sq ft living room needs about 3,500 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 6,100 BTU/hr.

Month by month in Two Rivers

Aug alone uses 41% of the year's cooling energy. The unit runs the equivalent of 260 hours a year at full output.

Two Rivers against nearby cities

Of 98 Wisconsin cities here, Two Rivers has the lowest cooling load. The range runs from Two Rivers at 20,200 BTU/hr to La Crosse at 29,800.

Where Two Rivers's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Two Rivers, 1 miles from the center of Two Rivers at 589 ft above sea level. That is close enough that the station's summers are Two Rivers's summers.

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

The sun over Two Rivers in late July

At 44.16°N, the noon sun on 21 July stands 66.2° above the horizon over Two Rivers and the day runs 14 h 49 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.

11,214 people live in Two Rivers, the 87th largest of the 98 Wisconsin cities sized on this site. Coordinates used: 44.1561, -87.5774.

Two Rivers AC sizing questions