What size AC for Española, NM? 3 tons for 2,000 sq ft

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

3 tons central AC or heat pump, about 32,200 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 30% 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 3 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 745 square feet in this climate. For a single room, size by the room: 16.1 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Espanola (0.7 mi away). Jul is the hottest month, averaging a high of 91.3°F and a low of 56.6°F, with about 51 days a year at 90°F or more. That gives a design temperature of 97°F against 75°F inside.

What it costs to run

About 859 kWh a year at SEER2 14.3, or roughly $132 at New Mexico's average residential rate of 15.34¢ per kWh. Cooling runs 4 months of the year here.

What drives the load in Española

Of the 32,200 BTU/hr, 15,840 comes through walls, roof and windows on a 97°F afternoon (49%), 13,000 is sun on the house (40%), 2,120 is four people and their appliances, and 1,200 is moisture the coil has to wring out of Española'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 30,960 BTU/hr before the moisture allowance.

Other house sizes in Española

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,400 BTU/hr; a 350 sq ft living room needs about 5,600 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 9,700 BTU/hr.

Month by month in Española

Jul alone uses 41% of the year's cooling energy. The unit runs the equivalent of 382 hours a year at full output.

Española against nearby cities

Of 19 New Mexico cities here, Española has the 16th highest cooling load. The range runs from Las Vegas at 25,500 BTU/hr to Sunland Park at 44,800.

Where Española's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Espanola, 0.7 miles from the center of Española at 5,620 ft above sea level. That is close enough that the station's summers are Española's summers.

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

The sun over Española in late July

At 36.00°N, the noon sun on 21 July stands 74.4° above the horizon over Española and the day runs 14 h 05 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.

10,475 people live in Española, the 19th largest of the 19 New Mexico cities sized on this site. Coordinates used: 36.0040, -106.0701.

Española AC sizing questions