What size AC for Phenix City, AL? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 43,100 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.6 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 557 square feet in this climate. For a single room, size by the room: 21.5 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Columbus Metro Airport (6.7 mi away). Jul is the hottest month, averaging a high of 92.9°F and a low of 73.5°F, with about 81 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 3,980 kWh a year at SEER2 14.3, or roughly $657 at Alabama's average residential rate of 16.51¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Phenix City

Of the 43,100 BTU/hr, 18,000 comes through walls, roof and windows on a 100°F afternoon (42%), 13,000 is sun on the house (30%), 2,120 is four people and their appliances, and 9,900 is moisture the coil has to wring out of Phenix 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 33,120 BTU/hr before the moisture allowance.

Other house sizes in Phenix City

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,200 BTU/hr; a 350 sq ft living room needs about 7,500 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,900 BTU/hr.

Month by month in Phenix City

Jul alone uses 22% of the year's cooling energy. The unit runs the equivalent of 1,322 hours a year at full output.

Phenix City against nearby cities

Of 66 Alabama cities here, Phenix City has the 6th highest cooling load. The range runs from Boaz at 30,600 BTU/hr to Montgomery at 44,000.

Where Phenix City's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Columbus Metro Airport, across the line in Georgia, 6.7 miles from the center of Phenix City at 394 ft above sea level. That is close enough that the station's summers are Phenix City's summers.

1 other city uses the same station and get the same climate inputs. The closest to Phenix City: Columbus (10 mi away, 3.9 mi from the station). Phenix City is farther from the station than 1 of them.

The sun over Phenix City in late July

At 32.45°N, the noon sun on 21 July stands 77.9° above the horizon over Phenix City and the day runs 13 h 49 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.

38,509 people live in Phenix City, the 13th largest of the 66 Alabama cities sized on this site. Coordinates used: 32.4537, -85.0310.

Phenix City AC sizing questions