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

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

3.5 tons central AC or heat pump, about 39,300 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.3 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 611 square feet in this climate. For a single room, size by the room: 19.7 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Galveston (10.8 mi away). Aug is the hottest month, averaging a high of 90.5°F and a low of 79.2°F, with about 57 days a year at 90°F or more. That gives a design temperature of 96°F against 75°F inside.

What it costs to run

About 5,195 kWh a year at SEER2 14.3, or roughly $833 at Texas's average residential rate of 16.03¢ per kWh. Cooling runs 9 months of the year here.

What drives the load in Texas City

Of the 39,300 BTU/hr, 15,120 comes through walls, roof and windows on a 96°F afternoon (38%), 13,000 is sun on the house (33%), 2,120 is four people and their appliances, and 9,100 is moisture the coil has to wring out of Texas City'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 30,240 BTU/hr before the moisture allowance.

Other house sizes in Texas City

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 6,900 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 11,800 BTU/hr.

Month by month in Texas City

Jul alone uses 19% of the year's cooling energy. The unit runs the equivalent of 1,890 hours a year at full output.

Texas City against nearby cities

Of 252 Texas cities here, Texas City has the 245th highest cooling load. The range runs from Levelland at 37,300 BTU/hr to Laredo at 51,500.

Where Texas City's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Galveston, 10.8 miles from the center of Texas City at 7 ft above sea level. That is close enough that the station's summers are Texas City's summers.

No other city in this set uses Galveston, so this sizing is Texas City's alone.

The sun over Texas City in late July

At 29.43°N, the noon sun on 21 July stands 81.0° above the horizon over Texas City and the day runs 13 h 37 min from sunrise to sunset. With the sun that close to overhead, the roof takes most of the heat at midday and the west wall takes the rest after 3 pm. Shorter days give the house a longer night to shed the day's heat.

57,875 people live in Texas City, the 66th largest of the 252 Texas cities sized on this site. Coordinates used: 29.4337, -94.8927.

Texas City AC sizing questions