What size AC for Shawnee, OK? 3.5 tons for 2,000 sq ft

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

3.5 tons central AC or heat pump, about 39,500 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 607 square feet in this climate. For a single room, size by the room: 19.8 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Shawnee 3nnw Mesonet (0.6 mi away). Jul is the hottest month, averaging a high of 92.6°F and a low of 71.7°F, with about 74 days a year at 90°F or more. That gives a design temperature of 99°F against 75°F inside.

What it costs to run

About 2,920 kWh a year at SEER2 14.3, or roughly $403 at Oklahoma's average residential rate of 13.81¢ per kWh. Cooling runs 6 months of the year here.

What drives the load in Shawnee

Of the 39,500 BTU/hr, 17,280 comes through walls, roof and windows on a 99°F afternoon (44%), 13,000 is sun on the house (33%), 2,120 is four people and their appliances, and 7,100 is moisture the coil has to wring out of Shawnee'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 32,400 BTU/hr before the moisture allowance.

Other house sizes in Shawnee

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 11,900 BTU/hr.

Month by month in Shawnee

Jul alone uses 27% of the year's cooling energy. The unit runs the equivalent of 1,056 hours a year at full output.

Shawnee against nearby cities

Of 45 Oklahoma cities here, Shawnee has the 41st highest cooling load. The range runs from Miami at 35,600 BTU/hr to Ardmore at 44,900.

Where Shawnee's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Shawnee 3nnw Mesonet, 0.6 miles from the center of Shawnee at 1,076 ft above sea level. That is close enough that the station's summers are Shawnee's summers.

No other city in this set uses Shawnee 3nnw Mesonet, so this sizing is Shawnee's alone.

The sun over Shawnee in late July

At 35.37°N, the noon sun on 21 July stands 75.0° above the horizon over Shawnee and the day runs 14 h 02 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.

32,092 people live in Shawnee, the 14th largest of the 45 Oklahoma cities sized on this site. Coordinates used: 35.3694, -96.9564.

Shawnee AC sizing questions