Evaporative cooling is one of the best possible ways to save electricity in the summer when Las Vegas temperatures rise to their peaks and your home AC just can’t keep up. A swamp cooler is the popular name for an evaporative style cooling system. There are swamp coolers big enough to cool an entire home and portable swamp coolers that are perfect for cooling one room at a time. There are even entirely non-powered swamp coolers that you can take with you on summer camping trips to places like Lake Mead or Valley of Fire State Park to beat the heat inside your tent.
That all sounds pretty great, right? Before you bust out a brand new swamp cooler in your living room or at your campsite, it’s important to understand how they work. Swamp coolers are not like normal AC units and they don’t even use the same technology to make a room cooler.
HOW DO SWAMP COOLERS WORK
The first thing to understand is that swamp coolers are nothing like a traditional AC. Normal ACs use a ton of electricity to keep refrigerant running through condenser coils which together create the cold that cools your air. Swamp coolers, on the other hand, work through the pure cooling power of evaporation. In fact, swamp coolers don’t even have to run the fan, but the fan helps to circulate the now-cooled air.
The way a swamp cooler works is the same way sweat works to cool down your skin. When water is evaporated into the air, it takes a certain amount of heat out of the air at the same time and replaces it with an aerated water droplet. It does this by soaking cooling pads in water and waiting for the pads to begin to dry via evaporation. The drying process really does cool down the air around the swamp cooler and a small fan can spread that cool air around.
SWAMP COOLERS WORK BEST IN LOW HUMIDITY
However, because swamp coolers work by adding water molecules to the air, they are also most effective in lower humidity environments. The drier your hot summer air is, the more powerful a swamp cooler can become. The reason for this is because dry air absorbs moisture through evaporation easier, causing the air to give up heat in return for moisture. The moist air not only cools the ambient temperature of the room, it can also act as a humidifier, making dry summers more bearable and less damaging to the skin.
Swamp coolers are generally ineffective in regions with high humidity. While they may technically function up to around 70% humidity, their cooling performance drops significantly as moisture in the air increases. Instead of feeling refreshed, you’re more likely to experience a muggy, uncomfortable atmosphere—sometimes even before humidity reaches that threshold. In such climates, traditional air conditioners are a far more reliable and efficient choice, offering consistent cooling and better humidity control.
HOW TO USE A SWAMP COOLER
Now let’s move onto what you really came here for: A quick and comprehensive guide on putting your swamp cooler to use.
FILL THE TANK / RESERVOIR WITH COOL TAP WATER
Start by filling the tank of your evaporative cooler. Whether you are camping or have the cooler plugged in next to your couch to cool you directly, it can’t work without water to soak up and evaporate. It’s best to start with cool tap water, about 50-degree water. When that cool water evaporates, it will further cool the air around your swamp cooler and the fan can blow that cooled air directly onto you.
Ice can offer a temporary boost to the coolth but does not actually increase the efficiency of the swamp cooler for cooling a room. In fact, because ice can’t absorb and evaporate without melting first, it can serve to slow down the cooling process overall.
LET THE PADS SOAK UP WATER
Once the reservoir is full, give your swamp cooler a little time for the pads to soak up the water before turning on the fan. This is how the cooler works. The pads wick moisture up from the reservoir then act as fins exposed to the air to promote cooling evaporation. If you start the fan before the pads have become moist and ready to evaporate, you’re just blowing around hot air. But if you wait about 5–15 minutes before filling, the cooler will be ready to go.
PRIMING THE PADS
Some swamp cooler users swear by priming the pads. This is done by pouring a little water over the pads to moisten them at the beginning of a cooling session. Priming the pads gets them initially wet so that the evaporation can begin. It also makes it easier and faster for the pads to wick moisture up from the reservoir as it gets started.
POINT THE FAN FOR GREATER EFFECT
Evaporative coolers are not as powerful as their electricity-hungry counterparts, but they can make you feel a lot cooler when used correctly. One of the best ways to optimize your swamp cooler is to point it at exactly where you want the cooling to happen. Swamp coolers are often pointed at the couch or seating area to keep you and your guests cool or at the dining room table for a cool summer dinnertime.
CONSIDER CRACKING THE WINDOWS
One interesting difference between swamp coolers and AC is that a swamp cooler can actually work better if you open the windows a bit. The reason for this, again, is the humidity. If the cooler is efficient, it will put a significant amount of cool moisture into the air which will, in turn, raise the humidity and lower the cooler’s efficiency. To keep your swamp cooler cooling, consider cracking a window to let out the current humid air and provide new dry air for the cooler to evaporate water into.
WHAT TO DO ON HUMID DAYS
Swamp coolers are notoriously inefficient in humid environments. On hot, muggy days when opening windows isn’t an option, their cooling power drops significantly. While pairing a swamp cooler with a dehumidifier can help, it’s a workaround rather than a solution. Dehumidifiers extract moisture from the air and collect it in a tank that must be emptied regularly. They then release drier air, which can slightly improve the swamp cooler’s performance.
However, this setup is far from ideal. It requires two separate appliances working in tandem just to achieve moderate cooling—something a single air conditioner can do more effectively and reliably. Even though swamp coolers and dehumidifiers may use less electricity, the trade-off in comfort and convenience often isn’t worth it in high humidity. For consistently cool, dry air—especially in sealed or humid spaces—a traditional air conditioner remains the more practical and dependable choice.
Using a swamp cooler is not nearly as complicated as you might think. Boiled down, all you need to do is fill, wait or prime the pads, then point the fan at wherever you want the cool air to go. If you have trouble, test the humidity and increase airflow or use a dehumidifier paired up to manage the moisture. For more information on how to stay cool this summer, contact us today at (702) 570-2721 or schedule an appointment online now.
