What size AC for West Monroe, LA? 3.5 tons for 2,000 sq ft

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

3.5 tons central AC or heat pump, about 41,300 BTU/hr of load

Here the 20 BTU per square foot chart lands close: 3.5 tons against a load of 3.4 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 581 square feet in this climate. For a single room, size by the room: 20.6 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Monroe Regional Airport (7.1 mi away). Aug is the hottest month, averaging a high of 93.6°F and a low of 71.4°F, with about 97 days a year at 90°F or more. That gives a design temperature of 101°F against 75°F inside.

What it costs to run

About 3,678 kWh a year at SEER2 14.3, or roughly $488 at Louisiana's average residential rate of 13.27¢ per kWh. Cooling runs 7 months of the year here.

What drives the load in West Monroe

Of the 41,300 BTU/hr, 18,720 comes through walls, roof and windows on a 101°F afternoon (45%), 13,000 is sun on the house (31%), 2,120 is four people and their appliances, and 7,400 is moisture the coil has to wring out of West Monroe's summer air (18%).

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 33,840 BTU/hr before the moisture allowance.

Other house sizes in West Monroe

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 3,100 BTU/hr; a 350 sq ft living room needs about 7,200 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 12,400 BTU/hr.

Month by month in West Monroe

Jul alone uses 22% of the year's cooling energy. The unit runs the equivalent of 1,274 hours a year at full output.

West Monroe against nearby cities

Of 35 Louisiana cities here, West Monroe has the 25th highest cooling load. The range runs from Covington at 37,800 BTU/hr to Natchitoches at 45,900.

Where West Monroe's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Monroe Regional Airport, 7.1 miles from the center of West Monroe at 73 ft above sea level. That is close enough that the station's summers are West Monroe's summers.

1 other city uses the same station and get the same climate inputs. The closest to West Monroe: Monroe (4 mi away, 2.8 mi from the station). West Monroe is farther from the station than 1 of them.

The sun over West Monroe in late July

At 32.51°N, the noon sun on 21 July stands 77.9° above the horizon over West Monroe and the day runs 13 h 50 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.

12,476 people live in West Monroe, the 28th largest of the 35 Louisiana cities sized on this site. Coordinates used: 32.5123, -92.1511.

West Monroe AC sizing questions