What size AC for North Bend, OR? 1.5 tons for 2,000 sq ft

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

1.5 tons central AC or heat pump, about 15,700 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 167% 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 1.5 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 1,526 square feet in this climate. For a single room, size by the room: 7.9 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at N Bend Sw Oregon Regional Airport (0.6 mi away). Aug is the hottest month, averaging a high of 67.3°F and a low of 53.6°F, with about 0 days a year at 90°F or more. That gives a design temperature of 71°F against 75°F inside.

What it costs to run

About 10 kWh a year at SEER2 14.3, or roughly $2 at Oregon's average residential rate of 15.46¢ per kWh. Cooling runs 0 months of the year here.

What drives the load in North Bend

Of the 15,700 BTU/hr, 0 comes through walls, roof and windows on a 71°F afternoon (0%), 13,000 is sun on the house (83%), 2,120 is four people and their appliances, and 600 is moisture the coil has to wring out of North Bend'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 15,120 BTU/hr before the moisture allowance.

Other house sizes in North Bend

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 1,200 BTU/hr; a 350 sq ft living room needs about 2,800 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 4,700 BTU/hr.

Month by month in North Bend

Sep alone uses 40% of the year's cooling energy. The unit runs the equivalent of 9 hours a year at full output.

North Bend against nearby cities

Of 57 Oregon cities here, North Bend has the lowest cooling load. The range runs from North Bend at 15,700 BTU/hr to Ontario at 36,500.

Where North Bend's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is N Bend Sw Oregon Regional Airport, 0.6 miles from the center of North Bend at 17 ft above sea level. That is close enough that the station's summers are North Bend's summers.

1 other city uses the same station and get the same climate inputs. The closest to North Bend: Coos Bay (2 mi away, 2.3 mi from the station). North Bend sits closer to the station than any of them, so its numbers are the best measured of the group.

The sun over North Bend in late July

At 43.41°N, the noon sun on 21 July stands 67.0° above the horizon over North Bend and the day runs 14 h 45 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.

10,049 people live in North Bend, the 56th largest of the 57 Oregon cities sized on this site. Coordinates used: 43.4072, -124.2345.

North Bend AC sizing questions