What size AC for Hot Springs, AR? 4 tons for 2,000 sq ft

What size AC a 2,000 sq ft house in Hot Springs 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 Hot Springs Asos (3.2 mi away). Jul is the hottest month, averaging a high of 93.3°F and a low of 72.2°F, with about 78 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 3,467 kWh a year at SEER2 14.3, or roughly $476 at Arkansas's average residential rate of 13.74¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Hot Springs

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 Hot Springs'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 Hot Springs

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 Hot Springs

Jul alone uses 25% of the year's cooling energy. The unit runs the equivalent of 1,151 hours a year at full output.

Hot Springs against nearby cities

Of 39 Arkansas cities here, Hot Springs has the 3rd highest cooling load. The range runs from Harrison at 33,100 BTU/hr to Fort Smith at 44,000.

Where Hot Springs's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Hot Springs Asos, 3.2 miles from the center of Hot Springs at 505 ft above sea level. That is close enough that the station's summers are Hot Springs's summers.

No other city in this set uses Hot Springs Asos, so this sizing is Hot Springs's alone.

The sun over Hot Springs in late July

At 34.49°N, the noon sun on 21 July stands 75.9° above the horizon over Hot Springs and the day runs 13 h 58 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.

37,971 people live in Hot Springs, the 12th largest of the 39 Arkansas cities sized on this site. Coordinates used: 34.4894, -93.0503.

Hot Springs AC sizing questions