What size AC for Mentor, OH? 2.5 tons for 2,000 sq ft

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

2.5 tons central AC or heat pump, about 26,500 BTU/hr of load

The 20 BTU per square foot chart would put in 3.5 tons, about 59% 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 906 square feet in this climate. For a single room, size by the room: 13.2 BTU/hr per square foot.

The climate it is sized for

Climate from NOAA's 1991 to 2020 normals at Painesville 4 Nw (4.8 mi away). Jul is the hottest month, averaging a high of 82.3°F and a low of 66.9°F, with about 5 days a year at 90°F or more. That gives a design temperature of 86°F against 75°F inside.

What it costs to run

About 1,327 kWh a year at SEER2 14.3, or roughly $250 at Ohio's average residential rate of 18.81¢ per kWh. Cooling runs 5 months of the year here.

What drives the load in Mentor

Of the 26,500 BTU/hr, 7,920 comes through walls, roof and windows on a 86°F afternoon (30%), 13,000 is sun on the house (49%), 2,120 is four people and their appliances, and 3,500 is moisture the coil has to wring out of Mentor's summer air (13%).

Sun is the biggest share here, more than heat through the walls, so shading west windows and a light roof cut the size you need more than extra insulation would. Sensible heat totals 23,040 BTU/hr before the moisture allowance.

Other house sizes in Mentor

Single rooms with a window or mini-split unit: a 150 sq ft bedroom needs about 2,000 BTU/hr; a 350 sq ft living room needs about 4,600 BTU/hr; a 600 sq ft open plan kitchen and family room needs about 7,900 BTU/hr.

Month by month in Mentor

Jul alone uses 31% of the year's cooling energy. The unit runs the equivalent of 716 hours a year at full output.

Mentor against nearby cities

Of 176 Ohio cities here, Mentor has the 119th highest cooling load. The range runs from Conneaut at 24,100 BTU/hr to Hamilton at 31,500.

Where Mentor's weather numbers come from

The nearest NOAA station with full 1991 to 2020 normals is Painesville 4 Nw, 4.8 miles from the center of Mentor at 600 ft above sea level. That is close enough that the station's summers are Mentor's summers.

1 other city uses the same station and get the same climate inputs. The closest to Mentor: Painesville (5 mi away, 2.9 mi from the station). Mentor is farther from the station than 1 of them.

The sun over Mentor in late July

At 41.69°N, the noon sun on 21 July stands 68.7° above the horizon over Mentor and the day runs 14 h 35 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.

47,113 people live in Mentor, the 23rd largest of the 176 Ohio cities sized on this site. Coordinates used: 41.6902, -81.3359.

Mentor AC sizing questions