The most important factor to consider when purchasing an LG portable air conditioner is how powerful your unit needs to be, measured in British thermal units (Btu). (For more information on British thermal units, see the FAQ section below.)

The number of British thermal units you need is directly related to the size of the room you want to cool, measured in square feet. Too few, and it will be impossible to properly cool the room; too many, and the air conditioner's work cycle will be too short to adequately dehumidify the room. The air conditioner will work harder, wasting energy and perhaps shortening the life of the compressor.

The following are LG's recommendations based on room size:

•   8,000 Btu: 200 square feet
• 10,000 Btu: 300 square feet
• 12,000 Btu: 400 square feet
• 14,000 Btu: 500 square feet

LG portable air conditioners have a variety of features to consider when choosing the right model for your needs.

One convenient feature you’ll find on all LG portable air conditioners is the ability to switch between different operating modes: Cool, Fan, Dry, and Heat.

Cool: You can select any temperature between 60°F and 86°F and the unit functions as an air conditioner.

Fan: If you prefer to save some money on your electric bill, you can operate the unit in Fan mode. This shuts off the cooling element and engages a fan (high or low) to circulate air.

Dry: In this mode, the unit functions as a dehumidifier, removing moisture from the air without drastically affecting the overall temperature of the room.

Heat: Some of the high-end models also have a mode that turns the air conditioner into a portable heater that has the same temperature range as the Cool mode (60°F to 86°F).

Most LG portable air conditioners run at less than 55 decibels, which is about the volume of a standard refrigerator. Some of the high-end models feature low-noise performance and run closer to 44 decibels, which is only slightly louder than the ambient noise in a library.

Auto-restart: All of LG's portable air conditioners feature auto-restart. If there’s a power outage, this allows your air conditioner to reboot, automatically recalling the unit's previous settings.

Remote control: The less expensive LG portable air conditioners can be controlled remotely by using a small, handheld device that operates like a television remote. With more expensive models, you can control all aspects of the air conditioner via your smartphone with the LG SmartThinQ app. The app also allows you to remotely monitor the air temperature in the room where the air conditioner is located.

Timer: All LG portable air conditioners have a 24-hour programmable timer you can use to program the unit to turn on and off at specific times.

Although the variety of features plays a part in the cost of an LG portable air conditioner, the main driver of price is the unit’s power.

8,000 Btu: These models cost $320 to $330.

10,000 Btu: These models cost $370 to $400.

12,000 Btu: These models cost $460 to $500.

14,000 Btu: These models cost $600 to $700.

As pointed out above, it’s important to buy an LG portable air conditioner that has the right power for your room. But square footage isn’t the only variable that impacts the efficiency of an air conditioner. The following are a few other factors that affect an air conditioner’s performance.

• Ceiling height: Most rooms have a ceiling height of around 8 feet. This is factored into the number of British thermal units that you need to efficiently cool a room. If your ceiling is significantly higher than that, it increases the volume of air that needs to be cooled, so you’ll need to purchase a more powerful air conditioner.
• Location: Heat rises. The higher up your LG portable air conditioner is, the harder it will have to work. In other words, it’s harder for a unit to cool a 200-square-foot room on the third floor than it is to cool the same size room on the first floor.
• Climate: The hotter it is outside, the harder the air conditioner has to work to bring down the inside temperature. If you live in the American South, you might need an air conditioner that is up to twice as powerful that of someone who lives in the northern part of the country.
• Shade: If your home is shaded for any portion of the day, it means the sun isn’t beating down on the roof all the time. The result? The air conditioner won’t have to work as hard to keep your home cool.
• Insulation: Basically, insulation means how well a room can maintain a temperature. Running an air conditioner in a room with poor insulation is like trying to make ice in a freezer without closing the door. If you want the most efficient performance from your LG portable air conditioner, make sure your home is properly insulated and there are no drafts around the windows and doors.

Q. What is a British thermal unit?
A. You’ll find numbers for British thermal units on heaters and air conditioners. Without getting too technical, 1 British thermal unit (Btu) is roughly the amount of heat produced by burning a wooden kitchen match. With a heater, the number tells you the amount of heat that can be produced in an hour: the higher the number, the more powerful the heater. In an air conditioner, the number tells you how much heat can be removed from a room in an hour: the higher the number, the more powerful the air conditioner.
 

Q. Where should I position my air conditioner?
A. The unit should be placed on a level floor, close to a window, in a location that provides 20 inches of air space on all sides to allow for adequate circulation.
 

Q. Why do I need to place my LG portable air conditioner close to a window?
A. The air that comes out of the exhaust hose is very hot. If you don’t vent that hot air out of the room through a window, it will be impossible for the air conditioner to lower the temperature of the room.
 

Q. My unit is too far from an outlet. Can I use an extension cord?
A. No. An LG portable air conditioner should always be plugged directly into a wall outlet. Even if you do purchase an extension cord that won't overheat, it isn’t a permanent solution to the problem. The best solution is to hire an electrician to reposition the outlet so it’s in a more convenient location.