Portable air conditioners: How to buy the best one for your home

If you're dreading sweating it out at home this summer, a portable air conditioner could be the answer. These small units are designed to cool rooms with the help of a nearby window and a power cord.

With no expensive installation required, they can be a big help for those rooms that aren't climate controlled or just don't get quite enough air flow. They're also useful in buildings with windows that can't fit a standard window AC unit. Here's what you should know if you're considering purchasing a portable air conditioner. 

How portable air conditioners work

Portable air conditioners are different than window units. Portable air conditioners look more like tower fans or air purifiers. They're mini-fridge-size units that can sit easily in the corner of most rooms. 

Like the dryer vent that exits your home via a nearby window or wall fitting, portable air conditioners use a hose to vent moisture and exhaust out of your home. You'll likely get a window venting kit with your purchase, and it includes everything you'll need to hook up the hose to your window and seal off the rest of the window's open space. 

Your portable air conditioner will plug into a power outlet nearby and pull air through its system to cool it and circulate it throughout your space. Most units include a water reservoir to help dehumidify the air it is circulating. Other use their vent hose to evaporate that moisture. 

There are two main types, single or dual hose and they work differently. Let's take a look. 

Single-hose portable air conditioners

A single-hose portable air conditioner works by taking the stagnant, hot air inside your room, cooling it and then circulating it through your space.

Any excess warm air or moisture is vented out of your space through the portable air conditioner's window venting hose. These models, like this $290 one from SereneLife are typically more energy efficient than dual-hose models. 

Dual-hose portable air conditioners

Dual-hose models don't use the air inside your home. Instead, they pull fresh air from the outside through that hose attached to the window. That's the air the portable air conditioner will cool and then circulate through the room.

A second hose takes the excess warm air and moisture and vents it back out through the window. These units, like $500 this Honeywell model, will usually cool down a room faster.  

What to look for in a portable air conditioner

Once you've decided is a portable air conditioner is for you, there are a few things to consider. 

Plan where you'll put it

You may already know which room in your home needs cooling, but you'll also need to think about where you're going to put it. You'll need nearby access to an openable window that can serve as the venting source. You'll also need a nearby electrical outlet.

Pricing

Portable air conditioners aren't cheap. Small, personal models can cost around $50, but for a unit that will cool an entire room, you're likely to spend at least $200. The large and more powerful the unit, the more you'll pay.

Many models available online range from $250-$499 for rooms between 200-650 square feet. Seasonal items like air conditioners tend to go on sale in the off-season, so keep your eyes peeled for fall and winter deals. 

Sizing

Size matters! Cliche? Yes. True? Also yes. You need to know how big the room is to determine just how much circulating power you need to purchase. Portable air conditioners come in different sizes, and often that means different prices, too. 

Here's a quick guide, from air conditioner manufacturer Sylvane, with the assumption of 8-foot ceilings. 

1. 7,500 BTUs will cover 150 sq. ft. x 8-ft. ceiling = 1,200 cubic feet
2. 9,000 BTUs will cover 200 sq. ft. x 8-ft. ceiling = 1,600 cubic feet
3. 10,000 BTUs will cover 300 sq. ft. x 8-ft. ceiling = 2,400 cubic feet
4. 12,000 BTUs will cover 400 sq. ft. x 8-ft. ceiling = 3,200 cubic feet
5. 13,000 BTUs will cover 450 sq. ft. x 8-ft. ceiling = 3,600 cubic feet
6. 14,000 BTUs will cover 500 sq. ft. x 8-ft. ceiling = 4,000 cubic feet

Remember, BTU stands for British Thermal Unit, a measurement of how much heat an air conditioning unit can remove from a space per hour. Portable air conditioners use this unit to measure their cooling power, so the higher the BTU rating, the larger the room an air conditioner can cool. 

Small rooms: A 7,000-to-10,000 BTU unit can effectively cool rooms up to 300 square feet. This $310, 8,000 BTU  Black + Decker unit cools rooms up to 200 square feet. 

Medium rooms: For rooms between 350 and 700 square feet, you'll want a 11,000-to-14,000 BTU unit. This $290 Costway air conditioner cools rooms up to 400 square feet. 

Large rooms: Residential units top out around 14,000 BTU, enough for 700 square feet at most. For spaces larger than that, you'll need to look into commercial or industrial models. A unit that is too small for your space will run for too long and never effectively cool it to the temperature you want.

If you need portable cooling but don't want to pay commercial prices (they can soar into the thousands), consider buying multiple smaller units and placing them far apart. 

Extra features and helpful smarts

Once you've determined the right size unit, it's time to think about what extra features might enhance your experience. Here are a few common extras and example units.

Timer: Timers let you set cooling to start or stop after a certain amount of time or a certain time of day. 

Remote: A remote control will help you manage your climate control much more conveniently.

Oscillation: Some portable air conditioners also oscillate like a room fan, for a breezy feel.

Dehumidifying: Air conditioners that also dehumidify can help rooms feel less stuffy fast.

Auto: Like programmable thermostats, models with automation offer the option to set the unit to cool on its own according to desired temperature.

Smarts: Portable air conditioners with smarts have WI-Fi to connect to voice assistants for voice commands and routines or to a mobile app. 

Maintaining your portable air conditioner

Portable air conditioners have air filters to keep circulating air clean. It's a good idea to clean the filter out every two weeks for the best performance. You can wash these filters with dish soap and warm water. 

Because portable air conditioners also dehumidify to some extent, you'll also need to drain your unit's water collection tray, if it has one. Dual-hose models may not collect water if they vent most of the humidity out a second hose, so check your unit's care instructions to find out more. Drain the collection tray often, before or after use to prevent mold growth. 

Other than those two maintenance items, general dusting and wiping down will keep your unit looking fresh and working well. If you store it in cold weather months, keep it in a cool, dry place. 

With a little bit of math and planning, you can solve your summer heat problems before they ruin the season with a portable air conditioner for your space.