What size AC for Texarkana, TX? 3.5 tons for 2,000 sq ft

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

3.5 tons central AC or heat pump, about 40,400 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.4 tons. This is one of the climates the chart was written for.

If a contractor quotes you more than 3.5 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 594 square feet in this climate. For a single room, size by the room: 20.2 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Texarkana Webb Field (5.6 mi away). Aug is the hottest month, averaging a high of 92.8°F and a low of 71.3°F, with about 83 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 3,316 kWh a year at SEER2 14.3, or roughly $532 at Texas's average residential rate of 16.03¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Texarkana

Of the 40,400 BTU/hr, 18,000 comes through walls, roof and windows on a 100°F afternoon (45%), 13,000 is sun on the house (32%), 2,120 is four people and their appliances, and 7,300 is moisture the coil has to wring out of Texarkana'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 33,120 BTU/hr before the moisture allowance.

Other house sizes in Texarkana

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,000 BTU/hr; a 350 sq ft living room needs about 7,100 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,100 BTU/hr.

Month by month in Texarkana

Jul alone uses 24% of the year's cooling energy. The unit runs the equivalent of 1,174 hours a year at full output.

Texarkana against nearby cities

Of 252 Texas cities here, Texarkana has the 243rd highest cooling load. The range runs from Levelland at 37,300 BTU/hr to Laredo at 51,500.

Where Texarkana's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Texarkana Webb Field, across the line in Arkansas, 5.6 miles from the center of Texarkana at 380 ft above sea level. That is close enough that the station's summers are Texarkana's summers.

1 other city uses the same station and get the same climate inputs. The closest to Texarkana: Texarkana (6 mi away, 1.4 mi from the station). Texarkana is farther from the station than 1 of them.

The sun over Texarkana in late July

At 33.45°N, the noon sun on 21 July stands 77.0° above the horizon over Texarkana and the day runs 13 h 54 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.

35,971 people live in Texarkana, the 105th largest of the 252 Texas cities sized on this site. Coordinates used: 33.4492, -94.0850.

Texarkana AC sizing questions