How do we test room air conditioners?

In Consumption Reports, we test room air conditioners in a room with a special climate, where we test three sizes of window air conditioners, small, medium and large.

Then we adjust the room size to the appropriate room size for each air conditioner, until we reach a temperature of 32 degrees Celsius, then we measure the time it takes for the air conditioner to lower the temperature by 10 degrees Celsius, and we also measure the extent to which the air conditioner maintains the set temperature.

 Because air conditioners can be noisy, we measure how loud each unit is at the lowest and highest settings.

Things to take into consideration:

Research on energy economy:

To cool a room uniformly, you’ll need to direct the air directly to its center, so check whether your air conditioner needs to blow air to the right or to the left, as some have a lever that makes it easier to direct.

To get the most out of your window air conditioner, it must be installed correctly. Most units are intended for double-hung windows, but if you have casement windows, you may want to consider purchasing a wall air conditioner. 

Some air conditioners have longer warranties than others, so when you purchase a new unit, check the manufacturer’s website for information, and ask the seller about the warranty for the brand and model you are considering.

Sizing your options:

Before considering price and features, start by determining what size unit you need for the space you want to cool, as well as where you will place the unit, as window air conditioners have cooling capacities ranging from 5,000 to 12,500 BTUs.

To be able to know the size of your room, multiply the length of the room by its width, but do not buy based on thermal units only. Many companies also recommend making an allowance for other considerations, such as the height of the ceiling in the place where you want to place the unit, and the size of windows and doorways. In addition to:

• If the room is heavily shaded, reduce the capacity by 10%.
• If the room is very sunny, increase the capacity by 10%
• If more than two people regularly occupy the room, add 600 BTUs for each additional person.
• If the unit is used in the kitchen, increase the capacity by 4,000 BTUs

Which design is right for you?

Some small window units cost less than $150, making them a tempting proposition, but only if you need to cool a very small space. If you need to cool a larger space, you will need to focus your search on the units that best match your space.

Almost all of the window units we tested meet the latest standards, which make them at least 10% more efficient than units without that certification. Standout models feature quiet operation, convenient controls, and operate under low voltage.

Window air conditioners:

portable air conditioners:

Our latest air conditioner tests found that portable air conditioners aren’t as good at cooling as manufacturers claim, plus they’re more expensive, more noisy, and use more energy than similarly sized window units.

It also weighs 23 to 37 kilograms, making it cumbersome and useless for rolling across carpets or thresholds. 

Ductless air conditioners:

This system is more expensive than window or portable units, and less than central air conditioning.

Ductless air conditioners are a smart way to add air conditioning to a limited number of rooms without having to open up walls to install ductwork, as you do with a central air system.

 Although we have not tested ductless air conditioners recently, all of our previous tests succeeded in providing good cooling functions and were quieter indoors and outdoors compared to window air conditioners, as their sound is barely audible even on the low setting.

However, if you are looking to cool the majority of your home, a central air conditioning system is likely the more cost-effective option.