What size AC for Auburndale, FL? 4 tons for 2,000 sq ft

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

4 tons central AC or heat pump, about 44,000 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 546 square feet in this climate. For a single room, size by the room: 22 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Winter Haven Gilbert Airport (4.2 mi away). Jul is the hottest month, averaging a high of 92.9°F and a low of 75.4°F, with about 121 days a year at 90°F or more. That gives a design temperature of 101°F against 75°F inside.

What it costs to run

About 6,172 kWh a year at SEER2 14.3, or roughly $946 at Florida's average residential rate of 15.32¢ per kWh. Cooling runs 12 months of the year here.

What drives the load in Auburndale

Of the 44,000 BTU/hr, 18,720 comes through walls, roof and windows on a 101°F afternoon (43%), 13,000 is sun on the house (30%), 2,120 is four people and their appliances, and 10,200 is moisture the coil has to wring out of Auburndale'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 33,840 BTU/hr before the moisture allowance.

Other house sizes in Auburndale

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,300 BTU/hr; a 350 sq ft living room needs about 7,700 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 13,200 BTU/hr.

Month by month in Auburndale

Jul alone uses 15% of the year's cooling energy. The unit runs the equivalent of 2,006 hours a year at full output.

Auburndale against nearby cities

Of 173 Florida cities here, Auburndale has the 13th highest cooling load. The range runs from Miami Shores at 36,500 BTU/hr to Plant City at 44,900.

Where Auburndale's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Winter Haven Gilbert Airport, 4.2 miles from the center of Auburndale at 143 ft above sea level. That is close enough that the station's summers are Auburndale's summers.

6 other cities use the same station and get the same climate inputs. The closest to Auburndale: Winter Haven (6 mi away, 1.8 mi from the station), Lakeland (10 mi away, 12.1 mi from the station), Haines City (11 mi away, 9.3 mi from the station), Davenport (12 mi away, 11.3 mi from the station), Bartow (15 mi away, 12.7 mi from the station). Auburndale is farther from the station than 1 of them.

The sun over Auburndale in late July

At 28.11°N, the noon sun on 21 July stands 82.3° above the horizon over Auburndale and the day runs 13 h 32 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.

20,659 people live in Auburndale, the 118th largest of the 173 Florida cities sized on this site. Coordinates used: 28.1100, -81.7973.

Auburndale AC sizing questions