What size AC for Ozark, AL? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 43,100 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.6 tons. This is one of the climates the chart was written for.

If a contractor quotes you more than 4 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 557 square feet in this climate. For a single room, size by the room: 21.5 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Dothan Regional Airport (15.1 mi away). Jul is the hottest month, averaging a high of 93.3°F and a low of 72.7°F, with about 89 days a year at 90°F or more. That gives a design temperature of 100°F against 75°F inside.

What it costs to run

About 4,219 kWh a year at SEER2 14.3, or roughly $697 at Alabama's average residential rate of 16.51¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Ozark

Of the 43,100 BTU/hr, 18,000 comes through walls, roof and windows on a 100°F afternoon (42%), 13,000 is sun on the house (30%), 2,120 is four people and their appliances, and 9,900 is moisture the coil has to wring out of Ozark's summer air (23%).

Heat through the shell is the biggest share here, so insulation and air sealing cut the size you need more than shading would. Sensible heat totals 33,120 BTU/hr before the moisture allowance.

Other house sizes in Ozark

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,200 BTU/hr; a 350 sq ft living room needs about 7,500 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,900 BTU/hr.

Month by month in Ozark

Jul alone uses 21% of the year's cooling energy. The unit runs the equivalent of 1,401 hours a year at full output.

Ozark against nearby cities

Of 66 Alabama cities here, Ozark has the 7th highest cooling load. The range runs from Boaz at 30,600 BTU/hr to Montgomery at 44,000.

Where Ozark's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Dothan Regional Airport, 15.1 miles from the center of Ozark at 368 ft above sea level. That is close enough that the station's summers are Ozark's summers.

1 other city uses the same station and get the same climate inputs. The closest to Ozark: Dothan (21 mi away, 6.2 mi from the station). Ozark is farther from the station than 1 of them.

The sun over Ozark in late July

At 31.45°N, the noon sun on 21 July stands 78.9° above the horizon over Ozark and the day runs 13 h 45 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.

14,368 people live in Ozark, the 53rd largest of the 66 Alabama cities sized on this site. Coordinates used: 31.4516, -85.6450.

Ozark AC sizing questions