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

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

3.5 tons central AC or heat pump, about 40,400 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.4 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 594 square feet in this climate. For a single room, size by the room: 20.2 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Crestview FAA/Airport (4.1 mi away). Jul is the hottest month, averaging a high of 92.4°F and a low of 71.1°F, with about 98 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 3,684 kWh a year at SEER2 14.3, or roughly $564 at Florida's average residential rate of 15.32¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Crestview

Of the 40,400 BTU/hr, 18,000 comes through walls, roof and windows on a 100°F afternoon (45%), 13,000 is sun on the house (32%), 2,120 is four people and their appliances, and 7,300 is moisture the coil has to wring out of Crestview'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 33,120 BTU/hr before the moisture allowance.

Other house sizes in Crestview

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 7,100 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,100 BTU/hr.

Month by month in Crestview

Jul alone uses 21% of the year's cooling energy. The unit runs the equivalent of 1,304 hours a year at full output.

Crestview against nearby cities

Of 173 Florida cities here, Crestview has the 104th highest cooling load. The range runs from Miami Shores at 36,500 BTU/hr to Plant City at 44,900.

Where Crestview's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Crestview FAA/Airport, 4.1 miles from the center of Crestview at 154 ft above sea level. That is close enough that the station's summers are Crestview's summers.

No other city in this set uses Crestview FAA/Airport, so this sizing is Crestview's alone.

The sun over Crestview in late July

At 30.75°N, the noon sun on 21 July stands 79.7° above the horizon over Crestview and the day runs 13 h 42 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.

30,727 people live in Crestview, the 97th largest of the 173 Florida cities sized on this site. Coordinates used: 30.7479, -86.5793.

Crestview AC sizing questions