What size AC for Ardmore, OK? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 44,900 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 534 square feet in this climate. For a single room, size by the room: 22.5 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Ardmore (2.2 mi away). Jul is the hottest month, averaging a high of 95.3°F and a low of 74.5°F, with about 81 days a year at 90°F or more. That gives a design temperature of 102°F against 75°F inside.

What it costs to run

About 3,963 kWh a year at SEER2 14.3, or roughly $547 at Oklahoma's average residential rate of 13.81¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Ardmore

Of the 44,900 BTU/hr, 19,440 comes through walls, roof and windows on a 102°F afternoon (43%), 13,000 is sun on the house (29%), 2,120 is four people and their appliances, and 10,400 is moisture the coil has to wring out of Ardmore'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 34,560 BTU/hr before the moisture allowance.

Other house sizes in Ardmore

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 7,900 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 13,500 BTU/hr.

Month by month in Ardmore

Jul alone uses 24% of the year's cooling energy. The unit runs the equivalent of 1,261 hours a year at full output.

Ardmore against nearby cities

Of 45 Oklahoma cities here, Ardmore has the highest cooling load. The range runs from Miami at 35,600 BTU/hr to Ardmore at 44,900.

Where Ardmore's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Ardmore, 2.2 miles from the center of Ardmore at 841 ft above sea level. That is close enough that the station's summers are Ardmore's summers.

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

The sun over Ardmore in late July

At 34.20°N, the noon sun on 21 July stands 76.2° above the horizon over Ardmore and the day runs 13 h 57 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.

25,064 people live in Ardmore, the 18th largest of the 45 Oklahoma cities sized on this site. Coordinates used: 34.1965, -97.1318.

Ardmore AC sizing questions