EER rating is the energy efficiency ratio of an air conditioner.
Energy efficient portable air conditioners have EER ratings of 7.0 to more than 9.0. The highest EER available is 9.3 EER in a portable AC. These units are significantly more efficient than the average of 5.5 to 6.5 EER you will find when researching this kind of room air conditioner.
Definition of portable AC efficiency: There is no set definition of high efficiency, and no portable air conditioners are given the Energy Star certification. The reason they are not eligible for Energy Star consideration is explained below.
Overview of High Efficiency Portable Air Conditioners
This graph shows you the availability of the most efficient portable air conditioners (180 portable ac units studied). As you can see, there are a limited number of energy efficient units.
The most efficient portable air conditioner brands are discussed next.
High Efficiency Portable Air Conditioner Brands
Who makes the most efficient portable air conditioners?
Whynter makes the most high efficiency portable air conditioners including several above 9.0 EER. The main reason feature of the most efficient portable ACs from Whynter is their dual hose design that helps reduce infiltration of outside air – an issue discussed below. Our comprehensive list of portable air conditioners and efficiency show 12 Whynter models meeting the standard. Most of them are dual hose units.
Danby also places multiple models on the list that exceed 9.0 EER.
The majority of LG models are in the high efficiency range for 7.0 and higher. About half of Frigidaire’s units meet this standard. Other brands like Haier and Hisense make one to three high efficiency models.
Here’s a table that shows the brands making and how many units they currently offer that are at least 7.0 EER.
High Efficiency Portable AC Cost
The most efficient portable air conditioners cost $415 to $800 or more.
| BTUs | Cost Range |
| 8,000 | $415 – $550 |
| 10,000 | $440 – $665 |
| 11,000 – 12,000 | $475 – $700 |
| 13,000 – 14,000 | $495 – $825 |
The cost factors include single vs dual hose, efficiency, features such as WiFi or voice control, fan speeds and remote functions. Where you buy the AC is a factor too.
Buying tip: Shop around for the best price, because you’ll find a difference of $100 or more between sellers for the same models.
Are Dual Hose Portable ACs More Efficient?
Dual hose portable air conditioners have higher SACC vs ASHRAE ratings, but are they more efficient?
The answer is yes, on average, dual hose portable ACs are more efficient than single hose units. If you’re considering energy efficient models, start with Whynter.
There are 24-30 dual hose models available at any given time because availability fluctuates. More than half of them qualify as high efficiency portable air conditioners.
These include the most efficient models – dual hose Whynter portable air conditioners in the 9.0 to 9.3 EER range.
So
Here’s another efficiency tip – Look for an AC with an inverter style compressor. There aren’t many, but it’s also a key feature for energy efficiency.
Are ACs with Inverter Compressors More Efficient?
Yes they are. They use less energy to run, and here is why: An inverter compressor runs like cruise control. You set the indoor temperature you want, and the compressor runs at the speed needed to maintain that temperature. For example, on 78-degree days, the unit’s compressor will run at a lower speed than on 90-degree days when the room is extra hot.
Running at a lower capacity or speed means less energy use, of course, and that gives a significant boost to portable air conditioner efficiency.
Most portable air conditioner compressors are On/Off parts. If the AC is on, they run at 100% capacity. There’s no low or medium, though the fan speed settings might include low/med/hi. That’s how standard compressors are different from a variable compressor
Who makes inverter compressor portable air conditioners?
Danby, LG, Whynter, Midea, Hisense and Toshiba.
For the most efficient units, start with the first three brands in the list. Whynter’s dual hose inverter models are the most efficient available and cost around $500 to $550 from most retailers.
Why Portable ACs are Less Efficient Than Window ACs
Here’s the truth – Portable air conditioners are not as efficient as window air conditioners – not even close. The difference in the highest EER is 6.4 EER.
Window AC: Energy efficient range – 9.9 to 15.7 EER
Portable AC: Energy efficient range – 7.5 to 9.3 EER
What’s the difference between AC efficiency for window and portable units?
There are two reasons that portable air conditioners are not very energy efficient. The problems are explained in detail in the US Federal Register.
You can also check our most efficient window air conditioners post here.
Factor #1: Portable AC Ducts and Efficiency
First, they use a hose, also called a duct, to exhaust heat. The hoses are thin plastic – not at all insulated. And so, between the unit and the window, heat transfers through the cheap plastic duct back into your living space. Window units are half outside the window, and the heat absorbed from the room is directly dumped outside without any of it escaping back into the room.
Factor #2: Air Infiltration Affects Portable AC Efficiency
Secondly, a portable AC exhausts heat by blowing warm air out of the house. A window AC simply radiates the heat away through the fins at the back of the unit.
When the portable air conditioner blows out warm air, that air loss inside the room is made up by pulling air in from other rooms or from outside the room. And the infiltration air is warm and humid, typically, so much of the potential efficiency is lost.
ASHRAE vs DOE SACC Portable AC Efficiency Ratings
Portable AC efficiency used to be rated the same as other AC types – how many BTUs of heat can the unit remove per hour? That’s BTU/h. That was the basic approach designed by the American Society of Heating, Refrigeration and Air-Conditioning Engineers, or ASHRAE.
But the US Department of Energy, for better or worse, got involved in the rating system. Realizing the heat loss and makeup air issue, the DOE developed the Seasonally Adjusted Cooling Capacity, adopted in 2017.
Listed Efficiency: If there is only one efficiency rating listed for a portable air conditioner you’re considering, it is the new DOE SACC rating. Sometimes manufacturers still list both ASHRAE and SACC.
Some don’t list efficiency! If there’s no good news, don’t share any news – that seems to be the approach brands like Honeywell take. You won’t find any efficiency information on its portable air conditioners product page or in the product descriptions.
EER vs CEER
You’ll see both of these ratings listed, though not all manufacturers list both.
The US DOE Energy Star program defines these terms this way:
EER is Energy Efficiency Ratio: “The ratio of measured cooling output (in BTU per hour) to the measured average electrical energy input (in Watts).”
CEER is Combined Energy Efficiency Ratio: The ratio of measured cooling output (in BTU per hour) to measured average electrical energy input (in Watts) and measured standby/off-mode power consumption (in Watts.)
Note the only difference between the two? CEER adds in the amount of power the unit uses while it is plugged in but not running – defined as standby or off-mode power use. In our research, CEER and EER are often nearly the same, EER being slightly lower on many units.
Currently, 8,000 to 13,000 BTU room ACs must be rated at 12.1 CEER or above while 14,000 BTU units must be 11.8 CEER or higher. No portable air conditioners qualify.
What Is The Most Efficient Way To Run A Portable Air Conditioner?
- Keep the duct hose as compressed as possible to reduce heat transfer through it.
- Wrap insulation around the duct.
- Only run the unit when you are there.
- Turn the unit off when not in use.
- Close other doors and windows in the room.
- Clean the filter monthly.
- Turn off lights and electronics in the room that produce heat when not in use.
FAQ
How efficient are portable ACs?
They begin around 5.5 EER and range to 9.3 EER.
Are portable ACs more energy efficient?
No. They use 25% to 40% more energy than window air conditioners of the same size.
Do portable ACs use a lot of electricity?
Portable models consume an average of 1,000 to 3,000 watts based on efficiency and size.
What are the most efficient portable air conditioners?
Those with inverter compressors and dual hoses.
