What size AC for Grandview, WA? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 30,000 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 40% 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 801 square feet in this climate. For a single room, size by the room: 15 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Sunnyside (7.3 mi away). Jul is the hottest month, averaging a high of 88.2°F and a low of 54.4°F, with about 45 days a year at 90°F or more. That gives a design temperature of 94°F against 75°F inside.

What it costs to run

About 628 kWh a year at SEER2 14.3, or roughly $91 at Washington's average residential rate of 14.42¢ per kWh. Cooling runs 3 months of the year here.

What drives the load in Grandview

Of the 30,000 BTU/hr, 13,680 comes through walls, roof and windows on a 94°F afternoon (46%), 13,000 is sun on the house (43%), 2,120 is four people and their appliances, and 1,200 is moisture the coil has to wring out of Grandview's summer air (4%).

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 28,800 BTU/hr before the moisture allowance.

Other house sizes in Grandview

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,300 BTU/hr; a 350 sq ft living room needs about 5,300 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 9,000 BTU/hr.

Month by month in Grandview

Jul alone uses 42% of the year's cooling energy. The unit runs the equivalent of 300 hours a year at full output.

Grandview against nearby cities

Of 91 Washington cities here, Grandview has the 11th highest cooling load. The range runs from Burlington at 15,700 BTU/hr to Kennewick at 32,900.

Where Grandview's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Sunnyside, 7.3 miles from the center of Grandview at 747 ft above sea level. That is close enough that the station's summers are Grandview's summers.

1 other city uses the same station and get the same climate inputs. The closest to Grandview: Sunnyside (7 mi away, 0.6 mi from the station). Grandview is farther from the station than 1 of them.

The sun over Grandview in late July

At 46.24°N, the noon sun on 21 July stands 64.2° above the horizon over Grandview and the day runs 15 h 03 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.

11,599 people live in Grandview, the 85th largest of the 91 Washington cities sized on this site. Coordinates used: 46.2443, -119.9090.

Grandview AC sizing questions