- Choose the right number of BTUs for your room. While most windowless air conditioners list the number of BTUs in addition to the room size you can expect it to cool, keep in mind your needs may vary. Other factors to consider include how hot it is outside the room and to what temperature you want the room to be cooled, how well-insulated the room is, how high the ceiling is, how much heat will be generated from appliances in the room, how much heat will be generated by people in the room, and how much direct sunlight the room gets. Check the resources below for a formula to help you decide how many BTUs you should get.
- Consider a no-drip model. These kinds of windowless air conditioners reduce or eliminate the need to constantly drain the accumulated water, as water is either exhausted into the air or used to cool the unit so that it operates more efficiently.
- Decide if you want a built-in air purifier. For cleaner air in addition to a cooler home, choose a windowless air conditioner with a HEPA-grade air filter.
- Get an energy-efficient model. Review several models and compare how much power each one uses. Since windowless air conditioners use a lot of power, it can be worth it to invest in an energy-efficient model.
- Hot air produced by windowless air conditioners is exhausted through an exhaust hose and out a window through the use of a window kit. Choose a hose that's long enough for where you want to place your windowless air conditioner, and choose a window kit that's the right size for the window you want to exhaust to.
- Look at other features. Other things to consider include decibel rating, size of the unit, thermostat and timer capabilities, fan settings, whether or not the unit oscillates, whether or not a dehumidifier is included, whether or not the dehumidifier can be run separately, and whether or not the unit has a remote control.
- Read customer reviews. Search sites such as consumersearch.com (link in resources), to get additional info on the portable room air conditioners you're considering buying. Take special note of how loud the unit is, as it's difficult to tell just by decibel rating alone.
- Avoid extending the exhaust hose too long, as the longer it's extended, the more heat it will radiate back into the room.
- The more windowless air conditioners you search through, and the more customer reviews you read, the better your chance of finding the best.