What size AC for Rutland, VT? 2 tons for 2,000 sq ft

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

2 tons central AC or heat pump, about 22,500 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 87% 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 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 1,068 square feet in this climate. For a single room, size by the room: 11.2 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Rutland (1.1 mi away). Jul is the hottest month, averaging a high of 80.3°F and a low of 56.4°F, with about 4 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 391 kWh a year at SEER2 14.3, or roughly $94 at Vermont's average residential rate of 23.93¢ per kWh. Cooling runs 3 months of the year here.

What drives the load in Rutland

Of the 22,500 BTU/hr, 6,480 comes through walls, roof and windows on a 84°F afternoon (29%), 13,000 is sun on the house (58%), 2,120 is four people and their appliances, and 900 is moisture the coil has to wring out of Rutland's summer air (4%).

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 Rutland

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 1,700 BTU/hr; a 350 sq ft living room needs about 3,900 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 6,700 BTU/hr.

Month by month in Rutland

Jul alone uses 41% of the year's cooling energy. The unit runs the equivalent of 249 hours a year at full output.

Rutland against nearby cities

Of 4 Vermont cities here, Rutland has the lowest cooling load. The range runs from Rutland at 22,500 BTU/hr to Burlington at 25,700.

Where Rutland's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Rutland, 1.1 miles from the center of Rutland at 620 ft above sea level. That is close enough that the station's summers are Rutland's summers.

No other city in this set uses Rutland, so this sizing is Rutland's alone.

The sun over Rutland in late July

At 43.61°N, the noon sun on 21 July stands 66.8° above the horizon over Rutland and the day runs 14 h 46 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. Long days mean the house keeps gaining heat into the evening, well after the outdoor peak.

15,565 people live in Rutland, the 3rd largest of the 4 Vermont cities sized on this site. Coordinates used: 43.6097, -72.9778.

Rutland AC sizing questions