What size AC for Crossville, TN? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 27,300 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 54% 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 878 square feet in this climate. For a single room, size by the room: 13.7 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Crossville Mem Airport (2.8 mi away). Jul is the hottest month, averaging a high of 83.2°F and a low of 64.4°F, with about 7 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 1,237 kWh a year at SEER2 14.3, or roughly $171 at Tennessee's average residential rate of 13.8¢ per kWh. Cooling runs 5 months of the year here.

What drives the load in Crossville

Of the 27,300 BTU/hr, 8,640 comes through walls, roof and windows on a 87°F afternoon (32%), 13,000 is sun on the house (48%), 2,120 is four people and their appliances, and 3,600 is moisture the coil has to wring out of Crossville'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 23,760 BTU/hr before the moisture allowance.

Other house sizes in Crossville

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 4,800 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 8,200 BTU/hr.

Month by month in Crossville

Jul alone uses 31% of the year's cooling energy. The unit runs the equivalent of 647 hours a year at full output.

Crossville against nearby cities

Of 65 Tennessee cities here, Crossville has the lowest cooling load. The range runs from Crossville at 27,300 BTU/hr to Memphis at 41,200.

Where Crossville's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Crossville Mem Airport, 2.8 miles from the center of Crossville at 1,865 ft above sea level. That is close enough that the station's summers are Crossville's summers.

No other city in this set uses Crossville Mem Airport, so this sizing is Crossville's alone.

The sun over Crossville in late July

At 35.95°N, the noon sun on 21 July stands 74.4° above the horizon over Crossville and the day runs 14 h 05 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.

12,785 people live in Crossville, the 51st largest of the 65 Tennessee cities sized on this site. Coordinates used: 35.9515, -85.0306.

Crossville AC sizing questions