What size AC for Gatesville, TX? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 43,900 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.7 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 546 square feet in this climate. For a single room, size by the room: 22 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Gatesville (3.1 mi away). Aug is the hottest month, averaging a high of 96.2°F and a low of 71.7°F, with about 110 days a year at 90°F or more. That gives a design temperature of 104°F against 75°F inside.

What it costs to run

About 3,896 kWh a year at SEER2 14.3, or roughly $625 at Texas's average residential rate of 16.03¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Gatesville

Of the 43,900 BTU/hr, 20,880 comes through walls, roof and windows on a 104°F afternoon (48%), 13,000 is sun on the house (30%), 2,120 is four people and their appliances, and 7,900 is moisture the coil has to wring out of Gatesville's summer air (18%).

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 36,000 BTU/hr before the moisture allowance.

Other house sizes in Gatesville

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,300 BTU/hr; a 350 sq ft living room needs about 7,700 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 13,200 BTU/hr.

Month by month in Gatesville

Aug alone uses 22% of the year's cooling energy. The unit runs the equivalent of 1,269 hours a year at full output.

Gatesville against nearby cities

Of 252 Texas cities here, Gatesville has the 204th highest cooling load. The range runs from Levelland at 37,300 BTU/hr to Laredo at 51,500.

Where Gatesville's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Gatesville, 3.1 miles from the center of Gatesville at 826 ft above sea level. That is close enough that the station's summers are Gatesville's summers.

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

The sun over Gatesville in late July

At 31.44°N, the noon sun on 21 July stands 79.0° above the horizon over Gatesville 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.

16,388 people live in Gatesville, the 183rd largest of the 252 Texas cities sized on this site. Coordinates used: 31.4387, -97.7460.

Gatesville AC sizing questions