5 Common Portable Air Conditioner Mistakes

Portable air conditioners are useful in a wide range of situations:

  • great alternatives to window or wall air conditioners p12bmedium
  • a supplement to central cooling units
  • in apartment buildings that do not permit window units
  • in homes that cannot accommodate central AC ducts

While generally convenient and energy efficient, choosing the wrong type of portable cooler for your home or work place can leave you sweltering in the heat or worse. Here are the top five mistakes consumers make when choosing a portable air conditioning unit:

  1. Purchasing the wrong type of cooler
  2. Miscalculating BTUS
  3. Ignoring EER
  4. Improper venting
  5. Electrical power problems

Read on so you know how to avoid these mistakes.

1) Purchasing the Wrong Type of Cooler for a Given Environment

Consumers often mistakenly interchange the terms "portable air conditioner" and "swamp cooler." Although both types of portable coolers lower the temperature of the air, they utilize completely different cooling methods and are each best suited for different types of environments.


Portable air conditioners cool the air by drawing air over cold, refrigerated coil which lowers the temperature and causes condensation. The cold, dehumidified air is dispersed into the room. The transferred heat from the air is expelled outside by an exhaust hose, while the condensate water is collected in an internal drain bucket. Some portable air conditioners use advanced auto-evaporative technology which eliminates the need for emptying the water tank.



In contrast, swamp or evaporative coolers consist of a large fan walled in by water-soaked pads. The fan blows the hot air through the pads and as the water evaporates, the air is cooled by as much as 20 degrees. The fan then blows this cooled, humidified air throughout an area or room.


Because portable ACs also function as dehumidifiers, they're best suited for areas with moderate humidity levels. Swamp coolers add moisture to the air and work best in dry climates, such as the Southwestern states. If the humidity level in your environment is above 20%, a swamp cooler will not work effectively to provide cooling.

Click here to read more about Air Conditioners vs Swamp Coolers.

2) Miscalculating BTUs and Room Size

Conventional wisdom says that the "right way" to choose an air conditioner is to simply choose the biggest, most powerful unit you can afford. Usually, this method doesn't work. Here's why.

The standard measurement for comparing air conditioners' power and cooling capacity is British Thermal Units, or BTUs. The higher the BTU rating, the stronger the air conditioner. But when it comes to air conditioners, bigger isn't always better.

It's crucial to match the BTU rating to the size of the area you wish to cool Having a portable AC with a BTU rating that is too high for the area you're cooling can be just as unsatisfactory as having one that is too low.


When the BTU rating is too high, the unit will cycle off and on too quickly and will not properly remove humidity from the other hand. The result will be cool, clammy air, not the dry, conditioned air that is so refreshing.



On the other hand, if the BTUs are too few, the unit will have to work harder, and probably not be able to adequately cool your area.

Click here to read more to see our chart of recommended BTUs by square footage.

3) Ignoring EER Ratings

EER, or the Energy Efficient Ratio, is a measure of how efficiently a cooling system will operate when the outdoor temperature is at a specific level - usually 95°F. EER is calculated as a simple ratio of BTUs to the amount of power a unit consumes in watts in an hour.

Here is an example using an air conditioner with 12,000 BTUs and consuming 1500 watts per hour:

EER = BTUs / Watts
12,000 / 1500 = 8
EER = 8

While it's true that the higher the EER and BTUs, the more efficient the cooling system, many consumers make the mistake of purchasing oversized units and ignoring EER ratings. The following is an example of an air conditioner with 12,000 BTU's and 1200 watts:

12,000 / 1200 = 10
EER =10

This would mean that this second unit can produce the same amount of cooling but uses fare less energy. Therefore, to save money on your monthly electric bill, choose a cooling system by getting an appropriately sized unit with a high EER.

Click here to read more about EER.

4) Improper Venting

ac10000eventingIf you decide to purchase a portable air conditioner, it's important to understand that the unit will need to be vented, either through a window, wall, or drop ceiling. The hot air and moisture pulled from the air during cooling need to go somewhere other than back into the room, or your AC won't be effective.

Most portable ACs come with venting kits which include a hose and window kit that fits into a variety of window styles and sizes. Additional attachments can be purchased to vent the exhaust through a wall. Installing a vent through a window usually takes no more than five minutes. You can read more about how to properly vent your AC by clicking here.

5) Electrical Power Problems

efore you make a purchase, make sure you have sufficient electrical power available for the unit to prevent breaking a fuse, as these units usually require a decent amount of power. Pay attention to the type of plug in your wall outlet, and keep in mind that smaller portable air conditioners only require 115-volt outlets, but might need a dedicated circuit.

Larger units, on the other hand, may require a 230/280-volt circuit.

If you have questions about selecting the right portable air conditioner, call us today and talk to one of our home cooling experts. We'll be happy to guide you through your purchase.

To view our selection of portable air conditioners for sale, click here. We have great online discounts, and free ground shipping is available on hundreds of in-stock items.


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