What size AC for Sebring, FL? 3.5 tons for 2,000 sq ft

What size AC a 2,000 sq ft house in Sebring 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 Sebring 23 Sse (22.6 mi away). Jul is the hottest month, averaging a high of 91.4°F and a low of 71.2°F, with about 119 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 4,920 kWh a year at SEER2 14.3, or roughly $754 at Florida's average residential rate of 15.32¢ per kWh. Cooling runs 12 months of the year here.

What drives the load in Sebring

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 Sebring'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 Sebring

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 Sebring

Aug alone uses 16% of the year's cooling energy. The unit runs the equivalent of 1,780 hours a year at full output.

Sebring against nearby cities

Of 173 Florida cities here, Sebring has the 123rd highest cooling load. The range runs from Miami Shores at 36,500 BTU/hr to Plant City at 44,900.

Where Sebring's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Sebring 23 Sse, 22.6 miles from the center of Sebring at 150 ft above sea level. That is close enough that the station's summers are Sebring's summers.

No other city in this set uses Sebring 23 Sse, so this sizing is Sebring's alone.

The sun over Sebring in late July

At 27.47°N, the noon sun on 21 July stands 82.9° above the horizon over Sebring and the day runs 13 h 29 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.

11,795 people live in Sebring, the 161st largest of the 173 Florida cities sized on this site. Coordinates used: 27.4714, -81.4516.

Sebring AC sizing questions