What size AC for Lovington, NM? 3.5 tons for 2,000 sq ft

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

3.5 tons central AC or heat pump, about 39,700 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.3 tons. This is one of the climates the chart was written for.

If a contractor quotes you more than 3.5 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 604 square feet in this climate. For a single room, size by the room: 19.9 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Hobbs 13w (16 mi away). Jun is the hottest month, averaging a high of 94.4°F and a low of 64.7°F, with about 101 days a year at 90°F or more. That gives a design temperature of 102°F against 75°F inside.

What it costs to run

About 2,755 kWh a year at SEER2 14.3, or roughly $423 at New Mexico's average residential rate of 15.34¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in Lovington

Of the 39,700 BTU/hr, 19,440 comes through walls, roof and windows on a 102°F afternoon (49%), 13,000 is sun on the house (33%), 2,120 is four people and their appliances, and 5,200 is moisture the coil has to wring out of Lovington's summer air (13%).

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 34,560 BTU/hr before the moisture allowance.

Other house sizes in Lovington

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,000 BTU/hr; a 350 sq ft living room needs about 7,000 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 11,900 BTU/hr.

Month by month in Lovington

Jul alone uses 23% of the year's cooling energy. The unit runs the equivalent of 991 hours a year at full output.

Lovington against nearby cities

Of 19 New Mexico cities here, Lovington has the 6th highest cooling load. The range runs from Las Vegas at 25,500 BTU/hr to Sunland Park at 44,800.

Where Lovington's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Hobbs 13w, 16 miles from the center of Lovington at 3,836 ft above sea level. That is close enough that the station's summers are Lovington's summers.

No other city in this set uses Hobbs 13w, so this sizing is Lovington's alone.

The sun over Lovington in late July

At 32.94°N, the noon sun on 21 July stands 77.5° above the horizon over Lovington and the day runs 13 h 52 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.

11,693 people live in Lovington, the 18th largest of the 19 New Mexico cities sized on this site. Coordinates used: 32.9445, -103.3492.

Lovington AC sizing questions