The Best Small-Space Air Conditioners to Cool Your Home

When summer temperatures climb, there's only so much a fan can do to cool down a room. Whether you live in an older home or are located in a climate with a short summer or just can't splurge for central air, an in-window or portable air conditioner unit makes sense. But where do you start? Gone are the days of buying expensive units that barely cooled a room and drove your energy bills sky-high. Newer AC units have evolved in terms of price and efficiency.

First, there's in-window air conditioners. While much hasn't changed in terms of design in decades—the units are boxy, heavy, and will take up the bottom half of your window—these classics are the most efficient way to cool down a room. The differences from brand to brand are based on Btus (British Thermal Units, which measure cooling capacity), energy efficient rating, dimensions, and ease of maintenance, rather than looks. In general, a unit will use 20 Btus per square foot to cool a room. Installation is relatively easy, though it involves muscle as units can weigh over 60 pounds. You slide the unit into the window, close the pane, then slide out extensions to keep the elements out of your interior. For additional support, wall-mounted brackets can be attached to your exterior wall.

If you need to cool a room without taking up half of a window, a portable air conditioner might make more sense. Though the units are freestanding, they still need access to a window in order to vent hot air out. (This is done through an exhaust hose that connects to the unit.) Portable units are just as heavy as in-window AC units, are generally more expensive, and consume more energy. Plus, they require a little more upkeep because you have to empty a water tank. However, a portable air conditioner unit is easier to install. One note: You'll see that portable air conditioner units have a Btu rating and/or a SACC (Seasonally Adjusted Cooling Capacity) rating. The latter is a new method of testing cooling capacity based on guidelines by the Department of Energy that measured Btus in a variety of conditions. SACC ratings have a lower Btu number than comparable capacity in-window air conditioner units, though the performance will be the same.

Ready to find your perfect air conditioning unit? Shop our top picks ahead.

Usually, in-window units under $200 are rated 5,000 BTU, giving LG's model an edge above the rest. This unit has three settings and three fan speeds, letting you customize the cooling levels to suit your comfort. With a 52 dBa (decibel rating), you can expect this to be as loud as a refrigerator running.

Shop Now: LG Electronics 6,000 BTU 115-Volt Window Air Conditioner with Remote, $226.59, homedepot.com.

Cooling rooms up to 350-square-feet, this in-window air conditioner gives you a bit more control over temperature thanks to a digital thermostat. It's also programmable, which is helpful if you're gone for long stretches of the day and want to cut down on energy consumption (without coming home to a hot home).

Shop Now: Frigidaire 8,000 BTU 115-Volt Window-Mounted Mini-Compact Air Conditioner with Temperature-Sensing Remote Control, $281.24, homedepot.com.

You'll have to pay a little more for an air conditioner that'll cool a larger room. This one does the trick with four-way air direction, three cooling speeds, three fan-only speeds, and a digital thermostat to let you precisely control the temperature. Plus, there's convenient extras like an Energy Saver mode that turns off the fan and compressor when your desired temperature is reached (saving energy costs), a filter cleaning reminder light and a handy remote.

Shop Now: GE 1,000-Square-Foot Window Air Conditioner (230-Volt, 18,000 BTU) Energy Star, $499, geappliances.com.

Finding a portable air conditioner under $300 can be a challenge. JHS' model is about as inexpensive as you can get without running into low ratings (or opting for a reconditioned model). Though it scores high with customers for its compact size, note that the range isn't very high—it's recommended for rooms that measure around 170-square-feet.

Shop Now: JHS 8,000 BTU Small Portable Air Conditioner, $313.86, amazon.com.

For a little bit more than the bargain-priced portable air conditioner, you can cool a room up to 450-square-feet in size. (Here, we see the complexities of comparing Btus under SACC, with this one measuring 6,500 Btus yet having a better cooling capacity than the JHS 8,000 Btu model.) The three-speed fan-only setting and the two-way air direction control also allows for maximum air circulation.

Shop Now: Insignia 450-square-foot Portable Air Conditioner, $529.99, bestbuy.com.

Now you can see the difference between an in-window and a portable air conditioning unit: price and power. This portable unit cools a room up to 500-square-feet, but costs more than the in-window unit that cools a space of double the size. Still, you're paying for convenience. There aren't a lot of portable air conditioners that'll cool this large of a space without having to consider industrial options. One big plus: The unit's advance auto-drain technology uses and recycles water collected during the cooling process (so you won't have to babysit the water tank).

Shop Now: Whynter ARC-14S 14,000 BTU Dual Hose Portable Air Conditioner, $523.59, amazon.com.