Room Air Conditioner Cost

• Window-mounted room air conditioners range from $100 -$300 to cool a room of 150-400 square feet (10x15- to 20x20-feet), and $300 -$800 or more for larger spaces. Generally, extra-quiet, energy-efficient models with remote controls are at the upper end of the price ranges. Extras such as extension kits to fill unused space in non-standard-sized windows, supporting platforms or other installation hardware can add $35 -$100.
• Through-the-wall models run about $240 -$600 to cool 150-400 square feet, and $300 -$1,500 or more for chilling larger areas; most appliance stores will arrange for installation for an additional $175 -$200. The extra-quiet, energy-efficient models with remote controls and/or heaters get the top prices.
• Portable residential units are about $400 -$650 for cooling up to 450 square feet (about 18x22-feet); portable commercial-grade air conditioners that cool larger areas cost $2,500 -$7,000 or more.

• For any type of air conditioner, it's important to carefully calculate how much cooling power is needed. Sun exposure, ceiling height and amount of wall insulation should all be considered. If the unit is too large for the space it wastes energy and won't properly de-humidify the indoor air; too small and it won't cool the space properly and could break down or wear out from overuse. If cooling several rooms, it's better to buy several small units than one large one.
• Window air conditioners are usually a fairly easy do-it-yourself installation and are mainly used to cool an apartment or one or two rooms. They are self-contained units with the hot end sitting outside the window and the cooling end inside. Most modern models are relatively quiet, but there is still some noise from the compressor. They block the view through the window and must either be removed and stored elsewhere during the cooler months or protected against the winter weather. The California Consumer Energy Center gives a detailed overview.
• A through-the-wall unit functions like a window model, but is permanently mounted in place. The noisy compressor is outside of the wall, muffling the sound; the view through the window is clear; and security is better because the unit cannot be easily removed to gain access to the house. The unit is held in place with a metal device called an air conditioner sleeve; it and the hole in the wall require either an extremely high level of do-it-yourself skill or professional installation. It may be difficult or impossible to install an air conditioner in a brick or masonry wall.
• Portable air conditioners require no installation for the unit, but must be vented through a window, a wall or a drop ceiling. Typically exhaust hoses are 4-7 feet long; making the exhaust hose any longer cuts the cooling power. These units collect water as they dehumidify the air, so either a bucket must be manually emptied or a drain line must be added to the back of the unit. Portable air conditioners are versatile and convenient, and can be used in workshops, garages, RVs, boats or other small spaces. ThisOldHouse.com installs a unit in a stuffy attic.

• If a window or wall has dry rot or other damage, carpentry or other repairs may be required before an air conditioner can be installed. The cost will depend on the extent of the problem.

• Save as much as 15-25 percent by buying during off-season store sales, in the cool months before the summer heat hits.
• Replacing a 10-year-old room air conditioner with an Energy Star model saves an average of $25 a year on electricity bills.

• When considering a particular model, be sure it matches with the electrical outlet where you plan to plug it in; some smaller air conditioners run on standard 120-volt household circuits, while others may need a dedicated circuit or a 240V outlet.
• Lowe's and Sears sell air conditioners and arrange for installation.

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