Although thousands of homes and families across the US have central air conditioning that doesn’t require a room-specific cooling unit, thousands more do not – and that’s where portable air conditioner units come in.
They may not be as efficient or effective as window AC units, but for those rooms where window units simply aren’t an option – due to limited window types, space or other restrictions – portable units are often better than nothing at all. At the very least, they can circulate air, take away some moisture and humidity in a room and make it feel more comfortable.
That said, there is a spectrum of quality and performance when it comes to portable units that makes one thing clear: you get what you pay for, and when you’re dealing with small appliances like this, it’s often worth taking the time and effort upfront to make sure you’re getting something that’s ideal for you and the rooms you wish to cool.
In the rest of this article, we’ll review some of the basics of portable AC units, how to choose one based on your needs, and what to look for in specific types of units, such as those that are small or quiet, which are often what we find many people are focused on when shopping for a portable air conditioner.
“Think of portable air conditioners as the cooling choice of last resort,” writes Consumer Reports. “They’re better than a fan but not much.”
That’s the sentiment we’ve found permeates the industry, but that doesn’t mean you can’t find a good, effective unit for your room. Here’s how to start shopping around.
How Portable Air Conditioners Work
With window AC units, the unit pumps in cool air and takes out warm air that is then distributed outside. Because the main unit is outside, the components and processes in the unit don’t affect the temperature of the room.
With portable units, however, everything is inside the room, including the unit and its functions. This means that as much as you can cool the room, it will be at least somewhat heated by the processes constantly going on within the air conditioner, which is in the room being cooled.
This may seem like a minor difference, but it’s enough to make window air conditioners significantly more efficient than portable ones. Still, if you have to use a portable unit, you should find one that has a higher efficiency rating and better overall reviews. Several brands have a better reputation for making efficient units than others, and there’s always new models coming out each year that may or may not be an improvement on the last.
One other thing to consider with these units is the idea of portability: although they can be moved, you’re more likely to keep it in one place simply because most units in this category still weight between 40 and 80 pounds. So while you can scoot the AC from room to room as needed, most units end up becoming somewhat stationary due to their size and the fact that they still need to be hooked up to a window in order to vent out warm air.
The US Department of Energy offers standards on portable AC equipment and parts, as well as definitions of what these portable units entail exactly. They also offer information on choosing a room air conditioner and why it’s best to find a unit that matches the size of your room.
Of course, you’ll also consider other elements, like the amount of direct sun your room gets, but in general, you’ll want to stick to a portable unit that’s rated to cool the relative size of your room. A unit that’s too small won’t cool the room quick enough, and a unit that’s too large will cool the room down before enough moisture is removed from the room, which means it can feel sticky and clammy – more humid – than a properly sized unit would allow.
Choosing the Right Sized Unit
“Based on size alone, an air conditioner generally needs 20 Btu for each square foot of living space,” says the US Department of Energy. “Other important factors to consider when selecting an air conditioner are room height, local climate, shading, and window size.”
Most units that we’ve reviewed rate anywhere from 5,000 BTUs to 14,000 BTUs or more. Generally speaking, those in the 8k to 12k BTU range are enough for most rooms, but smaller rooms may only need a 5k unit and larger living rooms and such may require a 14,000 unit.
In most cases, we’ve found that you can get an efficient 8k to 12k unit that still cools the room effectively without wasting too much energy, though again, this ranges from model to model.
The Smallest Portable Air Conditioners
Because portable units are inside the space they cool, many users like to focus on finding the smallest possible units – that still work well. You can get a small AC that doesn’t take up much room, but also doesn’t cool down the air as well as a larger unit. In this case, then, it’s important to balance size and performance, and if you’re looking for the best, most effective small units, you’ll want to look at the size of your room and how much cooling power you really need.
We review some of the top small portable air conditioners and recommend models based on your needs and the size of your rooms being cooled.
The Quietest Portable Air Conditioners
Aside from space, one of the most important considerations people make when buying a portable unit is the sound level. Although nearly all appliances give off some level of sound because of their components and processes, with portable air conditioners there’s a decent enough range of sound levels – measured in decibels – that it warrants finding a quiet unit if you’re a light sleeper, or if the unit will be used in an office or nursery where you’ll want to keep noise to a minimum.
We review some of the best options for quiet portable air conditioners and recommend those based on decibel level, cooling performance and other factors.
Further reading: A Guide to Energy-Efficient Heating and Cooling