Getting started - Air conditioner guide

Low prices and high efficiency make room air conditioners an inexpensive alternative to central air for cooling one or two rooms. Some 5,000- to 6,000-Btu units now cost less than $150. Our air-conditioner guide will help you choose what's right for you.

All the models we tested meet the 9.7 Energy Efficiency Ratio (EER) now required for small and medium-sized models below 8,000 British thermal units (Btu) per hour, and the 9.8 EER required for larger, 8,000- to 13,999-Btu models. Most also meet or exceed the 10.7 EER needed to qualify for Energy Star. And all now have electrical plugs that help prevent fires by shutting down if the power cord is damaged.

Find out whether replacing your air conditioner makes sense by using the savings calculator on the room air conditioners page at www.energystar.gov/index.cfm?c=roomac.pr_properly_sized. (Every 0.1 increase in EER translates into about a 1 percent drop in electricity use.) Also keep the following in mind:

Size it correctly

An air conditioner that's too small won't do a good job cooling a room. One that's too big cools the area so quickly that it doesn't have time to remove enough moisture, so it leaves you with a cold, clammy room.

Note the noise

Models that scored excellent or very good in our noise tests are so quiet that the only sound you might hear is the fan running. But air conditioners that scored fair for noise could disturb light sleepers when set on low and are distracting on high.

Factor in the window location

Air conditioners generally do a better job blowing air in one direction than in the other. That can be a problem if your window isn't centered on the wall. To uniformly cool a room, you'll need to direct air to its center, so check whether your A/C needs to blow air to the right or to the left.

Types of air conditioners

Most room models are designed to fit double-hung windows. Some fit casement and slider windows, and some are made for through-the-wall installation. To determine the proper size, measure the square footage of the area you want to cool. Increase capacity for a kitchen or a room usually occupied by more than two or three people.

Small air conditioners

Capacity ranges from 5,000 to 6,500 Btu/hr. Cool roughly 100 to 300 square feet.

Pros:They tend to be smallest, lightest, and least expensive.

Cons:They may not adequately cool a room measuring more than 300 square feet.

Midsized air conditioners

Midsized air conditioner Capacity ranges from 7,000 to 8,200 Btu/hr. Cool roughly 250 to 400 square feet.

Pros:They can generally handle a room measuring up to 400 square feet.

Cons:They tend to be more expensive, and their size and weight can make them harder to install and remove.

Large air conditioners

Capacities range from 9,800 to 12,500 Btu/hr. Cool roughly 350 to 650 square feet.

Pros:They can cool a large room up to about 650 square feet.

Cons:Bulk and weight make these models awkward and difficult to install. If an air conditioner is too powerful, the compressor might switch on and off repeatedly, so the unit doesn't lower the humidity sufficiently. That makes for a cold, damp room.

Friedrich

Friedrich is a smaller, more expensive brand of window air conditioners available at PC Richards and other appliance retailers. Window air units range in price from $500 to $1,200. Friedrich makes units with Btu from 5,000 to 24,000 and units that are Energy Star certified.

Frigidaire

Frigidaire air conditioners are available in independent and regional appliance retailers, as well as at Lowe's and Best Buy. Units range in price from $100 to $500, and in Btu from 5,000 to 25,000. Frigidaire makes units that are Energy Star certified.

GE

GE is the market-share leader in window air conditioners. This brand is available at a wide variety of independent and regional appliance retailers and at Sam's Club and Wal-Mart. GE's window air units range in price from $150 to $300, and in Btu from 5,000 to 25,000. GE makes units that are Energy Star certified.

Haier

Haier is available at Wal-Mart and BJ's, and at independent appliance dealers. Haier also markets window air conditioners under the Amana name. It makes Energy Star units. Prices range $100 to $500, and Btu from 5,000 to 24,000.

Kenmore

Kenmore air conditioners are made by LG and are sold at Sears and Kmart, for $100 to $500. Kenmore markets units with Btu from 5,000 to 24,000 and units that are Energy Star certified.

Kenmore (Sears)

Kenmore air conditioners are made by LG and are sold at Sears and Kmart, for $100 to $500. Kenmore markets units with Btu from 5,000 to 24,000 and units that are Energy Star certified.

LG

LG is a national brand available in a wide variety of independent and regional appliance retailers, as well as Home Depot and PC Richards. LG also markets lower-priced window air conditioners under the Goldstar name. Window air units range in price from $150 to $500, and in Btu from 5,000 to 25,000. The brand has units that are Energy Star certified.

Sharp

Sharp is a smaller player in the market. It is available at a wide variety of independent appliance retailers and at Costco and BJ's. Window air units range in price from $200 to $500. Sharp makes units with Btu from 5,000 to 12,000 and units that are Energy Star certified.