Size matters when you’re buying a window air conditioner. Buy too small and it will struggle to keep the room at a comfortable temperature; buy too big and and the room will cool too quickly without removing enough humidity from the air. Buy just right and you’ll be comfy and save money too. At Consumer Reports, we test air conditioners in the size rooms that they're intended to cool. Here are the best small, medium, and large window air conditioners from our tests. Bedroom or office (100 to 300 square feet) For a small bedroom, home office, or guest room you’ll want an air conditioner with good scores for comfort and quiet. The GE AEM05LV, $170, a CR Best Buy, aced our comfort tests and was very quiet on both low and high fan speeds. The LG LW6016R, $175, was also excellent at cooling a small room and was very quiet on the low fan setting but a little nosier on high. The Frigidaire FFRA0511R1, $125, was a little nosier but the price is right. Master bedroom or playroom (250 to 400 square feet)

To cool a bigger or busier room, you’ll want to step up to a mid-sized air conditioner.compressor for ac unit for home The GE AEM08LT, $300, was tops in its class with excellent scores for cooling a medium-size room. price for hvac package unitIt cruised through our brownout test, which tests if a unit can restart when voltage is low.  carrier thru wall ac unitsBut it was a bit noisy when the fan was on high. The LG LW8014ER, $240, a CR Best Buy, has very good scores for cooling and aced the brownout test.  It was also somewhat  noisy with the fan was on high. Living room or family room (350 to 650 square feet) For a living room or family room, you’ll want a large air conditioner, especially if you have an open floor plan.

The LG LW1214ER, $350, made our top picks list with its excellent scores for comfort. And despite its size, it operates at a quiet hum. The Haier HWE12XCR, $310, was excellent at cooling but nosier than the LG. But it bounces right back in brownout conditions. Size up your needs Window air conditioners typically have cooling capacities ranging from 5,000 to 12,500 British Thermal Units (BTUs). But don’t buy by BTU alone. As a rule of thumb, an air conditioner needs 20 BTU for each square foot of living space but there are other considerations such as the height of your ceiling and the size of your windows and doorways. Energy Star recommends that you make adjustments for the following circumstances: If the room is heavily shaded, reduce capacity by 10 percent. If the room is very sunny, increase capacity by 10 percent. If more than two people regularly occupy the room, add 600 BTUs for each additional person. If the unit is used in a kitchen, increase capacity by 4,000 BTUs.

To get the most from your window air conditioner, install it right. If your window is not in the center of your room, check that the direction of the airflow is into the room, not into the corner. Here are some tips from EnergySavers.gov. Make sure it’s level so the drainage system works effectively.Some larger units need a dedicated circuit. Don’t put lamps or TVs near the air conditioner’s thermostat as the heat will cause it to run longer. Set the thermostat as high as is comfortable, typically 78° F. You’ll appreciate the savings. Don’t dial the temperature down when you turn the air conditioner on—it won’t cool the room any faster. On humid days, set the fan speed on low; the slower air movement removes more moisture from the air. Use an extra fan to spread the cooled air around. Energy standards for window air conditioners are getting tougher, making them cheaper to run. Look for an Energy Efficiency Ratio of 10 or above. The higher the EER, the more efficient the air conditioner.

Look for models with filters that are easy to remove for regular cleaning. All the air conditioners in our tests have remote controls, digital displays, and timers that you can set to cool down the room before you get home. —Mary H.J. Farrell (@mhjfarrell on Twitter) Cools rooms up to 600 sq. ft. 3 fan speeds for preferred airflow Includes a remote and timer for convenience The Haier 14,000 BTU portable room air conditioner is capable of cool about 600 sq. ft. and also removing about 110 pint of moisture from the room per day. This portable air conditioner has exceptional power, 3 cooling speeds, electronic controls and a full function remote with 24 hour timer. Efficient dual exhaust hose design. Quiet operation and RoHS Compliant meaning it is made without the use of lead or mercury and using eco-friendly refrigerant. Includes casters to easily move the unit. 14,000 BTU designed to cool approximately 600 sq. ft. Auto-evaporation allows continuous operation without water removal

Includes a 46 in. extended window exhaust kit Fits double hung and sliding/casement windows 3 modes cool, dehumidify and fan 3 cooling speeds and 3 fan speeds 4 way air discharge Full function remote control 24 hour on/off timer Click Here to learn more about choosing the right Air Conditioner! Use and Care Manual A/C Cooling Rate (BTU/hr): A/C Coverage Area (sq. ft.): 1 Once the desired temperature is reached, does the fan continue to run to circulate air or does it shut off? 2 What if I dont have a window 2 How close to the window do you have to be? We have room that does not have a window How far can you run the vent 1 How do I service upper and lower drain plugs and how much water do they collect for windowless install How best do I and how often should I drain upper and lower drain plugs. Should I attach hose to lower drain plug and drain outside. I have enclosed patio room and want to bring air hoses and drain hose through lower aluminum panel to outside grass area.