What are Portable Air Conditioner Efficiency Ratings?

In this article, we’re going to discuss the two most commonly used energy efficiency ratings for portable air conditioners: Energy Efficiency Ratio (EER) and Combined Energy Efficiency Ratio (CEER).

Energy Efficiency Ratio

A portable air conditioner’s EER rating is the ratio of the unit’s cooling capacity to its power consumption.

• The higher a PAC’s EER rating, the lower your electricity costs will be for the same amount of cooling.
• EER ratings were introduced in 1975, and while many units still display these numbers, they are increasingly being replaced with CEER ratings.
• A unit’s EER rating is calculated with the following formula:

Combined Energy Efficiency Ratio

A portable air conditioner’s CEER rating is the ratio of the unit’s cooling capacity to its power consumption while in use combined with its standby/off-mode power consumption.

• As with EER ratings, the higher the number, the more efficient the personal air conditioner is.
• The CEER rating combines a PAC’s power output during performance with the energy it uses when it isn’t operating.
• This measurement was introduced by the Department of Energy in 2014 to provide a more accurate energy efficiency rating of room air conditioners, which increasingly have programmable and standby functions.
• A unit's CEER rating is calculated with the following formula:

When shopping for small portable air conditioners, it’s a good idea to consider both the EER and CEER ratings of the different units in order to get a more accurate idea of energy consumption. Keep an eye out for an ENERGY STAR label to determine which units are especially energy efficient.