What size AC for Steamboat Springs, CO? 2 tons for 2,000 sq ft

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

2 tons central AC or heat pump, about 24,700 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 70% 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 971 square feet in this climate. For a single room, size by the room: 12.4 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Steamboat Springs (0.9 mi away). Jul is the hottest month, averaging a high of 83.1°F and a low of 45.8°F, with about 6 days a year at 90°F or more. That gives a design temperature of 87°F against 75°F inside.

What it costs to run

About 94 kWh a year at SEER2 14.3, or roughly $16 at Colorado's average residential rate of 16.8¢ per kWh. Cooling runs 0 months of the year here.

What drives the load in Steamboat Springs

Of the 24,700 BTU/hr, 8,640 comes through walls, roof and windows on a 87°F afternoon (35%), 13,000 is sun on the house (53%), 2,120 is four people and their appliances, and 1,000 is moisture the coil has to wring out of Steamboat Springs'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 23,760 BTU/hr before the moisture allowance.

Other house sizes in Steamboat Springs

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 1,900 BTU/hr; a 350 sq ft living room needs about 4,300 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 7,400 BTU/hr.

Month by month in Steamboat Springs

Jul alone uses 59% of the year's cooling energy. The unit runs the equivalent of 55 hours a year at full output.

Steamboat Springs against nearby cities

Of 53 Colorado cities here, Steamboat Springs has the 52nd highest cooling load. The range runs from Boulder at 15,700 BTU/hr to Grand Junction at 36,500.

Where Steamboat Springs's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Steamboat Springs, 0.9 miles from the center of Steamboat Springs at 6,866 ft above sea level. That is close enough that the station's summers are Steamboat Springs's summers.

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

The sun over Steamboat Springs in late July

At 40.48°N, the noon sun on 21 July stands 69.9° above the horizon over Steamboat Springs and the day runs 14 h 28 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.

13,620 people live in Steamboat Springs, the 45th largest of the 53 Colorado cities sized on this site. Coordinates used: 40.4756, -106.8229.

Steamboat Springs AC sizing questions