Perfect for a variety of cooling situations, portable air conditioners are great alternatives to traditional air conditioning systems because they're compact, mobile, and require no permanent installation.  Moreover, because they're usually used to cool only certain parts of a home or as a supplement to central air conditioners, they can be much more cost-effective to run.

When deciding on a portable air conditioner, there are many important factors to consider. Some consumers may mistakenly purchase a portable AC that is inadequate for their cooling needs. Here are a few common mistakes to avoid when shopping for a portable air conditioner:

Purchasing the Wrong Type of Portable Cooler for Your Given Environment

Don't be confused by terms such as "portable air conditioner" and "air cooler," because these two appliances are quite different. While they both cool, they use completely different cooling methods to achieve lower ambient temperatures. Furthermore, portable air conditioners and air coolers (also known as "evaporative coolers" or "swamp coolers") have certain climate requirements.

Evaporative coolers use the simple process of evaporation to provide cooler air. A frame with a large fan is walled in by water-soaked pads, and this fan blows the warm outside air through the continually soaked pads to produce a cooling effect. As a result, the air can be cooled by as much as 20 degrees. Portable air conditioners use refrigerants to reduce the temperature. During the cooling process, moisture is condensed out of the air and collected in a drain bucket or exhausted out through a drain hose or evaporated out the exhaust. 

Climate Restrictions: These two types of portable coolers have climate restrictions. Because portable air conditioners act as dehumidifiers, they're best suited for areas with moderate humidity levels. On the other hand, swamp coolers add moisture to the air, so they are most effective in arid climates. Consequently, if the humidity level in your environment is above 20%, a swamp cooler will not work and a portable air conditioner will be more suitable.

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Ignoring BTUs and Your Room Size

The correct way to determine a portable AC's cooling efficiency is to calculate the unit's BTUs and hope the air conditioner will provide cooling comfort in a variety of conditions. But this method can sometimes be inaccurate.  A portable air conditioner's BTUs is a good predictor of its cooling ability, but some other factors should be considered, such as the dimensions of the room and where the AC will be placed.

BTU is an acronym for British Thermal Units and describes an air conditioner's cooling capacity.  The higher the BTU, the stronger the air conditioner. However, the size of the room you're cooling is also important, and if you choose a portable AC with an incorrect number of BTUs, cooling efficiency will be compromised.

A higher BTU rating than its corresponding room size will result in quick cycling and the inability to dehumidify the air.

Also, if a portable AC has a lower BTU rating than is required for a particular room, there will not be adequate cooling. When choosing a portable AC and its BTU requirements, consider your room's dimensions and where it will be located.

Shaded areas require a BTU reduction of 10%; sunny areas will require an increase in BTUs by 10%; and kitchens will need an addition 4,000 BTUs overall.

Ignoring EER

EER stands for "Energy Efficiency Ratio" and measures how efficient a cooling system will operate when the outdoor temperature is at a certain level (usually at 95° F). This measurement is calculated as a ratio of BTUs to the amount of power the portable air conditioner consumes in watts. The following is an example of how EER is calculated for an air conditioner with 12,000 BTUs and consuming 1500 watts:

BTUs / Watts = EER12,000 / 1500 = 8EER = 8

Here is an example of another portable AC with the same BTU rating but using 1200 watts of power.  This results in a higher EER:

12,000 / 1200 = 10

EER = 10

The above calculations show that the second portable AC produces the same amount of cooling as the first but is more energy efficient. With that said, if you want to save money on your energy costs, choose an appropriately sized portable air conditioner with a high EER.

Not Paying Attention to Venting Requirements

Despite the fact that portable air conditioners require no permanent installation, they will need to be vented either through a window, drop ceiling, or wall due to the fact that they exhaust hot air from indoors and work as humidifiers. Therefore, this moisture must be vented out with the use of a venting kit that is provided with your air conditioning unit. When purchasing a portable air conditioner, keep your venting requirements in mind, and if venting through a window, be sure the window you intend to install the vent on matches the type of window covered by the kit (i.e., sliding or casement-type windows).

Ignoring Power Considerations

Keep power considerations in mind when choosing a portable AC because insufficient power can cause a fuse to be broken. Pay attention to the plug type in your wall outlet and be aware that smaller portable ACs require 115-volt outlets but larger portable ACs may even require a 230/280-volt circuit.

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  • Portable ac units are now derated from old BTU sizes. So a 14,000 unit will cool what a 10,000 window unit will.

    use fans to push the air to warm areas.
    My unit pulls 11 amps so I connected it to the washing machine circuit through the wall.

    Jeff on

  • It would be great to see more information on maintaining the water evaporation rates and how often one must empty the containers ….. or if there is no hose to handle the humidity evaporation, whether or not that hose system is able to keep up with humidity in the Houston Texas area. People who live in Northern CA and Vegas commenting on the humidity feature is a bit of a joke to those who know what serious humidity be. So please, when commenting about humidity features, state where you are located; and if you live in the dry deserts, try to understand that your use of a dehumidifier is kinda useless information that just does not help. thanks for helping us sweaty southern folks with real reviews!!!!

    stickybits on

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