What size AC for Kinston, NC? 3.5 tons for 2,000 sq ft

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

3.5 tons central AC or heat pump, about 37,800 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.1 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 635 square feet in this climate. For a single room, size by the room: 18.9 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Kinston Ag Research (2 mi away). Jul is the hottest month, averaging a high of 90.6°F and a low of 71.4°F, with about 62 days a year at 90°F or more. That gives a design temperature of 97°F against 75°F inside.

What it costs to run

About 2,969 kWh a year at SEER2 14.3, or roughly $444 at North Carolina's average residential rate of 14.94¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Kinston

Of the 37,800 BTU/hr, 15,840 comes through walls, roof and windows on a 97°F afternoon (42%), 13,000 is sun on the house (34%), 2,120 is four people and their appliances, and 6,800 is moisture the coil has to wring out of Kinston'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 30,960 BTU/hr before the moisture allowance.

Other house sizes in Kinston

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,800 BTU/hr; a 350 sq ft living room needs about 6,600 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 11,300 BTU/hr.

Month by month in Kinston

Jul alone uses 25% of the year's cooling energy. The unit runs the equivalent of 1,124 hours a year at full output.

Kinston against nearby cities

Of 91 North Carolina cities here, Kinston has the 23rd highest cooling load. The range runs from Boone at 21,700 BTU/hr to Lumberton at 40,200.

Where Kinston's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Kinston Ag Research, 2 miles from the center of Kinston at 60 ft above sea level. That is close enough that the station's summers are Kinston's summers.

No other city in this set uses Kinston Ag Research, so this sizing is Kinston's alone.

The sun over Kinston in late July

At 35.28°N, the noon sun on 21 July stands 75.1° above the horizon over Kinston and the day runs 14 h 02 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.

19,519 people live in Kinston, the 53rd largest of the 91 North Carolina cities sized on this site. Coordinates used: 35.2751, -77.5934.

Kinston AC sizing questions