When summer heat and humidity hits for real, cold showers and box fans can only do so much. At some point you’ll need to actually cool the air in your house if you want to stay comfortable. Without central air conditioning, that can be a real struggle.
Central air is an incredible luxury with one huge, potentially deal-breaking flaw: It uses an outrageous amount of electricity, and the hotter it is outside, the more it needs. Just about every alternative to central air is cheaper and greener than the real thing. With the exception of whole-house fans, which are exactly what they sound like, all of these solutions are designed to cool individual rooms as needed. This minimizes energy costs and offers a ton of flexibility, so even renters have some options for beating the heat this summer.
A good ceiling fan can make a huge difference in hot, sticky weather. They’re easy on the electric bill and affordable enough that you might be able to convince your landlord to shell out for one. Just make sure yours is pointed the right way: Counter-clockwise is best for cooling.
One step up from a ceiling fan is a ventilator fan. You’ll usually see these used in bathrooms for moisture control purposes, but they can also be used to move air from a cooler area of your house to a hotter one. Ventilator fans are somewhere in the $100-200 range (not including installation), which is less expensive than many other options. However, as FamilyHandyman.com points out, a ventilator fan only works if you have “an abundance of existing cool air that’s easily accessible to your hot room.”
Single-room air conditioners
We all know and love (or at least tolerate) the classic “window rattler” AC unit, but you need the right type of windows to use one. These two other options work where window units don’t.
Portable AC units
These air conditioners exhaust through a window and are usually mounted on casters so they can be moved from room to room. They’re easy to install (and uninstall), but they’re fairly expensive up front and tend to use more power than other units of similar cooling capacity. If you’re cooling a studio apartment and your lease prohibits even semi-permanent AC installation, though, a portable unit is a good choice.
In-wall AC units
If you’re in a position to cut holes in walls, in-wall AC units offer at least two huge benefits over their window-mounted and portable counterparts: They’re more energy efficient and don’t take up precious window space. The installation process isn’t exactly DIY-friendly, however—you’ll want to get a professional involved, which adds to the cost.
Ductless mini split-system AC units (“mini splits”)
Mini splits are basically central air for people who can’t have central air. Here’s how they work, according to BobVila.com:
Mini-split systems typically consist of two separate units: an interior evaporator (with fan and cooling coil) and an outside condenser. The two pieces are linked by flexible tubing that runs cooled refrigerant from the outdoor compressor to the indoor unit for distribution. Because no ductwork is required, a mini-split particularly well suits both older homes and new room additions.
Like other single-room AC units, mini splits let you cool specific rooms. The main difference is that they allow you to run multiple units on one compressor, which uses less electricity than running the same number of individual units. A good mini split system isn’t cheap, but it’s an excellent (and surprisingly energy-efficient) way to keep the hottest rooms in your house cool for years to come.
If you own a house with an attic, you may be able to cool it down with a whole-house or attic fan—with a strong emphasis on “may.” An in-depth guide to whole-house fans from BobVila.com explains that this old-school cooling technique can cool large houses for a fraction of the cost of central air, but only in very specific circumstances.
Whole-house fans work by pushing hot air up and out of your house (usually through the attic) while simultaneously pulling cool air in through open windows below. At night, you open the windows and turn on the fan; in the morning, you close everything up. Unfortunately, this simple and effective system has a fatal flaw, which the BobVila.com guide spells out clearly:
Because whole-house fans draw fresh outdoor air into the home but do not dehumidify it, they work best in climates where outdoor humidity levels are already relatively low. … A whole-house fan isn’t advisable in Pensacola, Florida, where there’s an average humidity of 72.5 percent, but one could do some good in such places as Phoenix (with an average humidity level of 36.6 percent) or Las Vegas (30.3 percent).
In other words, if you live in a house with an attic in a dry climate with low overnight temperatures in the summer and mild winters—because leaky fans can cause heat loss—then a whole-house fan might be for you. But if humidity is a concern, don’t waste your time on fans alone.
This is a good reminder to consider your specific needs. Depending on your climate, housing materials, and ability to make modifications, some of these solutions will make more sense than others. Think through what you want, what you need, and what you can actually do, then take it from there.
This article was originally published on July 10, 2013. It was updated on May 24, 2021 with new links, a new photo, a new section on ceiling fans, and updated information. It was also edited to reflect Lifehacker’s current style guidelines.