What size AC for Richmond, TX? 4 tons for 2,000 sq ft
What size AC a 2,000 sq ft house in Richmond needs
4 tons central AC or heat pump, about 45,900 BTU/hr of load
Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.8 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 523 square feet in this climate. For a single room, size by the room: 22.9 BTU/hr per square foot.
The climate it is sized for
Climate from NOAA's 1991 to 2020 normals at Houston Sugarland Mem (6.7 mi away). Jul is the hottest month, averaging a high of 95°F and a low of 75.7°F, with about 112 days a year at 90°F or more. That gives a design temperature of 103°F against 75°F inside.
What it costs to run
About 5,318 kWh a year at SEER2 14.3, or roughly $852 at Texas's average residential rate of 16.03¢ per kWh. Cooling runs 9 months of the year here.
What drives the load in Richmond
Of the 45,900 BTU/hr, 20,160 comes through walls, roof and windows on a 103°F afternoon (44%), 13,000 is sun on the house (28%), 2,120 is four people and their appliances, and 10,600 is moisture the coil has to wring out of Richmond'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 35,280 BTU/hr before the moisture allowance.
Other house sizes in Richmond
| House | Load, BTU/hr | Size | 20 BTU/ft² chart |
|---|---|---|---|
| 1,000 sq ft | 24,300 | 2 tons | 2 tons |
| 1,500 sq ft | 35,100 | 3 tons | 2.5 tons |
| 2,500 sq ft | 56,600 | 5 tons | 5 tons |
| 3,000 sq ft | 67,400 | 5 tons | 5 tons |
Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,400 BTU/hr; a 350 sq ft living room needs about 8,000 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 13,700 BTU/hr.
Month by month in Richmond
| Month | Avg high | Cooling degree days | AC kWh |
|---|---|---|---|
| Jan | 64.3°F | 22 | 35 |
| Feb | 68.1°F | 40 | 63 |
| Mar | 74.1°F | 99 | 155 |
| Apr | 80.1°F | 185 | 291 |
| May | 87.1°F | 399 | 627 |
| Jun | 92.3°F | 546 | 858 |
| Jul | 95°F | 631 | 991 |
| Aug | 94.2°F | 618 | 971 |
| Sep | 89.7°F | 468 | 735 |
| Oct | 83.3°F | 257 | 404 |
| Nov | 73.6°F | 84 | 132 |
| Dec | 66.5°F | 35 | 55 |
Jul alone uses 19% of the year's cooling energy. The unit runs the equivalent of 1,658 hours a year at full output.
Richmond against nearby cities
| City | Distance | Design day | Size for 2,000 sq ft |
|---|---|---|---|
| Rosenberg, TX | 4 mi | 103°F | 4 tons |
| Sugar Land, TX | 8 mi | 103°F | 4 tons |
| Fulshear, TX | 11 mi | 103°F | 4 tons |
| Stafford, TX | 12 mi | 103°F | 4 tons |
| Missouri City, TX | 14 mi | 103°F | 4 tons |
| Katy, TX | 15 mi | 103°F | 4 tons |
Of 252 Texas cities here, Richmond has the 158th highest cooling load. The range runs from Levelland at 37,300 BTU/hr to Laredo at 51,500.
Where Richmond's weather numbers come from
The nearest NOAA station with full 1991 to 2020 normals is Houston Sugarland Mem, 6.7 miles from the center of Richmond at 77 ft above sea level. That is close enough that the station's summers are Richmond's summers.
6 other cities use the same station and get the same climate inputs. The closest to Richmond: Rosenberg (4 mi away, 11 mi from the station), Sugar Land (8 mi away, 2.3 mi from the station), Fulshear (11 mi away, 14.6 mi from the station), Stafford (12 mi away, 5.5 mi from the station), Missouri City (14 mi away, 8.3 mi from the station). Richmond is farther from the station than 2 of them.
The sun over Richmond in late July
At 29.58°N, the noon sun on 21 July stands 80.8° above the horizon over Richmond 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.
13,305 people live in Richmond, the 209th largest of the 252 Texas cities sized on this site. Coordinates used: 29.5812, -95.7605.
Richmond AC sizing questions
What size AC does a 2,000 sq ft house in Richmond, TX need?
About 4 tons, for a cooling load of 45,900 BTU/hr on a 103°F design day. That is one ton per 523 square feet in Richmond's climate.
Is 20 BTU per square foot right for Richmond?
The chart gives 3.5 tons for 2,000 sq ft, against 4 tons sized from NOAA's 1991 to 2020 normals at Houston Sugarland Mem. For a single room here, plan on 22.9 BTU/hr per square foot.
What does central AC cost to run in Richmond?
About $852 a year: 5,318 kWh at SEER2 14.3 and 16.03¢ per kWh, over 9 cooling months.