Area To Be Cooled (square feet)
100 to 150
150 to 250
250 to 300
300 to 350
350 to 400
400 to 450
450 to 550
550 to 700
700 to 1,000
1,000 to 1,200
1,200 to 1,400
1,400 to 1,500
1,500 to 2,000
2,000 to 2,500
Capacity Needed (BTUs per hour)
Low price and high efficiency make room air conditioners an inexpensive alternative to central air for cooling one or two rooms. By choosing an energy star qualified air conditioner, it would prevent 1.2 billion pounds of greenhouse gas emissions, the equivalent emissions from 100,000 cars. Energy star qualified room air conditioners often include timers for better temperature control, allowing you to use the minimum amount of energy you need to cool the room.
Many people buy an air conditioner that is too large thinking it will provide better cooling. However, an oversized air conditioner is actually less effective and wastes energy. A properly sized unit will remove humidity effectively as it cools.
Using the square footage and the chart below, determine the correct cooling capacity. Cooling capacity is measured in British thermal units (BTUs) per hour.
Make any adjustments for the following circumstances:
Condition without Dehumidification
(space feels damp and has musty odor only in humid weather)
(space always feels damp and has musty odor. Damp spots show on walls and floor.)
(space feels and smells wet. Walls or floor sweat, or seepage is present.)
(laundry drying, wet floor,high load conditions.)
500 sq ft
1,000 sq ft
1,500 sq ft
2,000 sq ft
2,500 sq ft
Dehumidifier capacity is usually measured in pints per 24 hours and is determined by two factors- the size of the space that needs to be dehumidified and the conditions that exist in the space before dehumidification. Use the chart below to estimate the capacity you are looking for. The energy efficiency of dehumidifiers is measured by its energy factor. A higher energy factor means a more efficient dehumidifier.
Source: Association of Home Appliance Manufacturers (AHA)