What size AC for Crawfordsville, IN? 2 tons for 2,000 sq ft

What size AC a 2,000 sq ft house in Crawfordsville 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 Crawfordsville 6 Se (5.8 mi away). Jul is the hottest month, averaging a high of 82.8°F and a low of 61.9°F, with about 12 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 1,002 kWh a year at SEER2 14.3, or roughly $171 at Indiana's average residential rate of 17.04¢ per kWh. Cooling runs 5 months of the year here.

What drives the load in Crawfordsville

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 Crawfordsville'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 Crawfordsville

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 Crawfordsville

Jul alone uses 31% of the year's cooling energy. The unit runs the equivalent of 558 hours a year at full output.

Crawfordsville against nearby cities

Of 88 Indiana cities here, Crawfordsville has the 85th highest cooling load. The range runs from Auburn at 24,100 BTU/hr to Jasper at 36,400.

Where Crawfordsville's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Crawfordsville 6 Se, 5.8 miles from the center of Crawfordsville at 836 ft above sea level. That is close enough that the station's summers are Crawfordsville's summers.

No other city in this set uses Crawfordsville 6 Se, so this sizing is Crawfordsville's alone.

The sun over Crawfordsville in late July

At 40.04°N, the noon sun on 21 July stands 70.4° above the horizon over Crawfordsville and the day runs 14 h 26 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.

16,594 people live in Crawfordsville, the 54th largest of the 88 Indiana cities sized on this site. Coordinates used: 40.0411, -86.8977.

Crawfordsville AC sizing questions