What size AC for Flowood, MS? 3.5 tons for 2,000 sq ft

What size AC a 2,000 sq ft house in Flowood 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 Jackson International Airport (1.2 mi away). Aug is the hottest month, averaging a high of 92.2°F and a low of 71.5°F, with about 85 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 3,542 kWh a year at SEER2 14.3, or roughly $533 at Mississippi's average residential rate of 15.06¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Flowood

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 Flowood'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 Flowood

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 Flowood

Jul alone uses 22% of the year's cooling energy. The unit runs the equivalent of 1,281 hours a year at full output.

Flowood against nearby cities

Of 41 Mississippi cities here, Flowood has the 32nd highest cooling load. The range runs from Brookhaven at 36,900 BTU/hr to Columbus at 44,000.

Where Flowood's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Jackson International Airport, 1.2 miles from the center of Flowood at 296 ft above sea level. That is close enough that the station's summers are Flowood's summers.

3 other cities use the same station and get the same climate inputs. The closest to Flowood: Pearl (5 mi away, 3.4 mi from the station), Brandon (6 mi away, 5.8 mi from the station), Canton (18 mi away, 19.4 mi from the station). Flowood sits closer to the station than any of them, so its numbers are the best measured of the group.

The sun over Flowood in late July

At 32.34°N, the noon sun on 21 July stands 78.1° above the horizon over Flowood 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.

10,853 people live in Flowood, the 38th largest of the 41 Mississippi cities sized on this site. Coordinates used: 32.3361, -90.0729.

Flowood AC sizing questions