What size AC for Atlantic City, NJ? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 26,400 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 59% more than this climate needs. An oversized unit cools the air fast, shuts off before it pulls moisture out, and leaves the house cold and clammy.

If a contractor quotes you more than 2.5 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 911 square feet in this climate. For a single room, size by the room: 13.2 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Atlantic City Marina (1.5 mi away). Jul is the hottest month, averaging a high of 80.3°F and a low of 70.5°F, with about 6 days a year at 90°F or more. That gives a design temperature of 84°F against 75°F inside.

What it costs to run

About 1,472 kWh a year at SEER2 14.3, or roughly $355 at New Jersey's average residential rate of 24.09¢ per kWh. Cooling runs 4 months of the year here.

What drives the load in Atlantic City

Of the 26,400 BTU/hr, 6,480 comes through walls, roof and windows on a 84°F afternoon (25%), 13,000 is sun on the house (49%), 2,120 is four people and their appliances, and 4,800 is moisture the coil has to wring out of Atlantic City's summer air (18%).

Sun is the biggest share here, more than heat through the walls, so shading west windows and a light roof cut the size you need more than extra insulation would. Sensible heat totals 21,600 BTU/hr before the moisture allowance.

Other house sizes in Atlantic City

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,000 BTU/hr; a 350 sq ft living room needs about 4,600 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 7,900 BTU/hr.

Month by month in Atlantic City

Jul alone uses 32% of the year's cooling energy. The unit runs the equivalent of 799 hours a year at full output.

Atlantic City against nearby cities

Of 116 New Jersey cities here, Atlantic City has the 111th highest cooling load. The range runs from Hackettstown at 26,400 BTU/hr to Camden at 34,300.

Where Atlantic City's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Atlantic City Marina, 1.5 miles from the center of Atlantic City at 10 ft above sea level. That is close enough that the station's summers are Atlantic City's summers.

2 other cities use the same station and get the same climate inputs. The closest to Atlantic City: Pleasantville (3 mi away, 4.6 mi from the station), Ocean City (11 mi away, 12 mi from the station). Atlantic City sits closer to the station than any of them, so its numbers are the best measured of the group.

The sun over Atlantic City in late July

At 39.38°N, the noon sun on 21 July stands 71.0° above the horizon over Atlantic City and the day runs 14 h 22 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.

38,959 people live in Atlantic City, the 23rd largest of the 116 New Jersey cities sized on this site. Coordinates used: 39.3773, -74.4511.

Atlantic City AC sizing questions