What size AC for Bullhead City, AZ? 5 tons for 2,000 sq ft

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

5 tons central AC or heat pump, about 60,800 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, which falls short here. On a design day the unit runs flat out and the house still drifts above 75°F by late afternoon.

If a contractor quotes you more than 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 394 square feet in this climate. For a single room, size by the room: 30.4 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Bullhead City (1.2 mi away). Jul is the hottest month, averaging a high of 110.7°F and a low of 81.1°F, with about 186 days a year at 90°F or more. That gives a design temperature of 119°F against 75°F inside.

What it costs to run

About 7,074 kWh a year at SEER2 14.3, or roughly $1,087 at Arizona's average residential rate of 15.36¢ per kWh. Cooling runs 9 months of the year here.

What drives the load in Bullhead City

Of the 60,800 BTU/hr, 31,680 comes through walls, roof and windows on a 119°F afternoon (52%), 13,000 is sun on the house (21%), 2,120 is four people and their appliances, and 14,000 is moisture the coil has to wring out of Bullhead City's summer air (23%).

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 46,800 BTU/hr before the moisture allowance.

Other house sizes in Bullhead City

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 4,600 BTU/hr; a 350 sq ft living room needs about 10,600 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 18,200 BTU/hr.

Month by month in Bullhead City

Jul alone uses 21% of the year's cooling energy. The unit runs the equivalent of 1,663 hours a year at full output.

Bullhead City against nearby cities

Of 44 Arizona cities here, Bullhead City has the highest cooling load. The range runs from Flagstaff at 24,000 BTU/hr to Bullhead City at 60,800.

Where Bullhead City's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Bullhead City, 1.2 miles from the center of Bullhead City at 531 ft above sea level. That is close enough that the station's summers are Bullhead City's summers.

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

The sun over Bullhead City in late July

At 35.13°N, the noon sun on 21 July stands 75.3° above the horizon over Bullhead City and the day runs 14 h 01 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.

43,266 people live in Bullhead City, the 26th largest of the 44 Arizona cities sized on this site. Coordinates used: 35.1274, -114.5560.

Bullhead City AC sizing questions