How to Clean Your Swamp Cooler and Cooler Pads

If your house has a swamp cooler instead of a traditional air conditioner, now is the time to make sure it’s in good shape and ready to run the minute the outdoor temperature starts to inch up. Evaporative coolers are a great alternative to air conditioning because they require far less power to operate, and they don’t rely on chemical refrigerants to get the job done. This makes evaporative cooling an affordable and eco-friendly way to beat the summer heat — provided you live in a reliably dry area where water can quickly dissipate into the atmosphere.Whether you rely on a whole house or portable swamp cooler, you need to thoroughly clean and inspect it each spring before you put it back into service. Swamp coolers sometimes get a bad rap for having a musty smell, but you can enjoy better air quality by giving it a good scrubbing before turning it on for the season. Here’s how to do it.

1. Drain the Swamp

Hopefully your evaporative cooler’s water tank was emptied and carefully dried before you turned it off for the season last year. This will go a long way toward preventing mold and mildew from developing while the appliance is in storage (or out of commission for several months). If not — or if you need to do a mid-season tune-up — your first step is to turn off the water supply and drain the water reservoir.  You’ll also want to turn off the power source so you can get in there without worrying about getting shocked.

How you drain the tank will depend on the model. A whole house cooling system will likely have a drain plug or valve to remove that lets the water out. If it doesn’t, you’ll need to use a garden hose to siphon the water out. A portable evaporative cooler may have a removable tank that you can simply pour down the drain; otherwise, you may have to tip the whole thing out on the ground outside.

2. Clean the Tank

How to Clean Your Swamp Cooler and Cooler Pads

Start by dry scrubbing the water reservoir with a stiff brush or the scouring side of a kitchen sponge to loosen any debris. If you have a good deal of loose dirt when this step is complete, consider using a vacuum cleaner to get rid of it. Otherwise, an ordinary dust pan should help you lift out loose particles.

Next, use soapy water (a tablespoon of dish soap in a gallon of warm water should do the trick) and scrub the inside of the water tank with a sponge to give it a through cleaning. If you have hard water, you could have mineral deposits in the tank, and mild soap won’t be enough to do the job. These may not scrub away easily with soap. If your local water has a high mineral content, fill the reservoir with white vinegar and allow the equipment to soak for an hour or two. The high acidity will help dissolve mineral deposits and clear the blockages that keep your machine from functioning properly. It also serves to disinfect the water tank to combat “swamp cooler smell.”

When the vinegar soak is complete, drain the vinegar and fill the tank with clean water. Use your sponge to make sure all surfaces are thoroughly rinsed, and drain the tank a final time.

3. Inspect the Tank and Parts

How to Clean Your Swamp Cooler and Cooler Pads

While the tank is empty, it’s the perfect time to check for any problems. Look for leaks or cracks where water may seep out of the water tank. While it’s unlikely that the sturdy reservoir of a portable air cooler will leak, metal seams in a whole house system can come apart over time. If you find a breach, thoroughly dry the area with a towel and apply a bead of silicone caulking to stop the leaks. Allow the caulk to dry according to the manufacturer’s instructions before continuing to add any liquids to the tank.

Now’s a good time to take a look at the float arm as well. If the arm doesn’t freely move up and down, it’s possible that mineral deposits are causing it to stick. Use a toothbrush or scouring pad to rub away corrosion — and consider using additional vinegar to help ease stubborn deposits.

Next, your swamp cooler’s motor and fan will also benefit from regular maintenance. If you can easily reach, apply a few drops of oil to lubricate these moving parts and keep things running smoothly.

Finally, check the belt on the fan if it’s easily visible. It should fit snugly and not hang loose. This important part can stretch or crack over time, so if it’s sagging or in bad shape, you should probably replace it. Check with the owner’s manual for replacement parts, or call a licensed service agent for assistance.

These swamp cooler maintenance tips are more commonly required in a whole house system than a portable one. The systems work in basically the same way, but you may not have easy access to the interior of a portable appliance, depending on its design.

4. Deodorize the System

How to Clean Your Swamp Cooler and Cooler Pads

If you discovered mildew or mold while cleaning — or if you just don’t want to take any chances on having your house smell musty when you turn on your swamp cooler for the season — now’s the time to add a fresh scent to your system. Fill a spray bottle with 15 to 20 drops of your favorite essential oil — lavender, mint or citrus scents work well. Then top off the bottle with fresh water and shake vigorously to combine. Spray this solution over the water pan and reservoir parts before refilling the tank with fresh water, and you should enjoy cool air and a fresh scent when you turn on your machine.

5. Inspect the Cooling Pads

How to Clean Your Swamp Cooler and Cooler Pads

The cooler pads are a crucial part of your evaporative cooling system. Because they are wet for long periods, they can be susceptible to mold and mildew. Therefore, it’s crucial to look them over thoroughly to decide if they’re in good enough shape to use. If you see any signs of mold, throw them away and get new pads — your nose will thank you for the fresh air, and you’ll protect your family from breathing in allergens that can cause respiratory issues.

If you need new ones, check the old pads to see what type you have. In general, you have two choices when it comes to swamp cooler pads: rigid media cooling pads or fiber pads, which are made from aspen wood shavings or cellulose. Some are designed to fit into your specific cooler model (much like a furnace or AC unit’s air filter), while others need to be cut to fit. If you need to buy your padding on a roll, be sure to hang on to your old fiber pads to use as a template when cutting new ones.

6. Clean Your Cooling Pads

If your cooling pads are intact and show no signs of mold or mildew, you can clean them instead of replacing them. To do this, remove the pad and use a vacuum cleaner to remove loose debris. Then place the pads on the ground outside and hose them off with clean water. Be sure to clean both sides. You’ll know you’re finished when the water runs clean off them — depending on when you last cleaned the pads, this could take a while, so have patience!

It’s fine to reinstall the pads while they are still wet, since this will get your evaporative cooler up and running faster. Once you have replaced the pads, you’re ready to put the unit back together and fill the water tank (or open the valve so it can fill on its own, if it’s already connected to your home’s water line). Plug the unit back in and turn it on, and soon you’ll have a room full of cold air that smells great, too.

How Often Should You Clean Your Swamp Cooler?

How often you need to clean your unit depends on a few factors. First, how often do you use it? In reliably dry climates, your evaporative cooler will be effective on a daily basis, and you may have it on all the time for weeks or even months on end. For heavy use, it’s a good idea to give it a full cleaning three times a year: Once before you begin use in the spring, once in the middle of the season, and once at the end before you pack it away. You’ll also want to drain the tank and refill it with fresh water at least once a month. This keeps the water from getting musty, and it gives you an opportunity to spray a bit of essential oil in the tank to add an extra scent, if you like.

How to Clean Your Swamp Cooler and Cooler Pads

The beauty of a portable evaporative cooler is that it may not need to be cleaned as often, since you’ll naturally change the water regularly as you refill the smaller tank. Their small size and easily removable water tanks make evaporative coolers much easier to clean, so the whole process is much faster. If you use your portable air cooler as a bridge to help you use your AC less, you may not have to clean it often if it’s not in heavy rotation — once at the beginning of the season and once at the end should be sufficient.


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How to Clean Your Swamp Cooler and Cooler Pads
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