Close-up of swamp cooler and the text: Best evaporative coolers for greenhouses

Best Evaporative Coolers for Greenhouses

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Summer can be a really tough time for greenhouse growers. Trust me, overheating can cause a lot of problems for your plants. So you’ll want to find a means to keep your greenhouse cool even in hot seasons. You don’t want to let all your efforts go down the drain, right?

Evaporative coolers are one great way to cool your greenhouse in summer. They are effective devices that can last you throughout the hot seasons, even if you live in regions where summer temperatures are really high.

Here, I’ve brought you the best evaporative coolers on the market. That’s not all! I’ve also included a comprehensive guide that’ll aid you throughout the buying process. Want to know more about evaporative coolers? Dive in!

What is an evaporative cooler?

An evaporative cooler, also known as the swamp cooler, is simply a device that cools air through the evaporation of water.

I guess now you are trying to figure out what evaporation has got to do with having cool air.

How do evaporative coolers work?

Evaporative coolers simply take hot air, with considerably low humidity, and process it by running it over water-saturated pads. This causes evaporation to take place. They then direct this humid/cool air indoors.

These devices use evaporative pads and a blower to achieve this. Usually, evaporative coolers are mounted on the outside of the greenhouse.

There’s a small opening used to blow the air into the greenhouse and an exhaust opening to remove the heated air.

Are evaporative coolers worth it?

Evaporative coolers are a good choice and probably the best air cooling option. Unlike alternative air cooling systems, they present a simple and natural solution on all fronts.

One way the evaporative cooler works is that a door or a window must be cracked open to let the stale/warm air out, while fresher and cleaner air is let in through the cooler.

This is opposed to air-conditioning systems that recycle the same air over and over again. Air released by the cooler is fresh, natural, and isn’t harsh on your beautiful plants.

These coolers are eco-friendly. They release a very minimal amount of greenhouse gases. This is impressive when compared to air conditioning systems. You’ll also find them more power-efficient. They’ll save you cash on power bills.

Evaporative coolers are much easier to install and maintain, and they are more affordable. It is an electric-powered device and doesn’t require much to run. No gases, no fuel. Just a simple humidifying device.

Evaporative cooler blowing out air with the text: Beat the Heat - Best Evaporative Coolers For Your Greenhouse

When evaporative coolers are NOT a good choice

Swamp coolers come with some disadvantages and are not always the go-to choice. If you are living in an area where it’s already very humid, for example, some Southern states, an evaporative cooler won’t help you much. As explained earlier, the system works by adding cool water molecules to the air. If the humidity level is close to 100%, there is not much room to cool down the air.

If you are living somewhere where the air is dry, you have good chances, unless it gets extremely hot and you want to maintain 75°F. Let’s take Arizona as an example. Swamp coolers work there amazingly because the humidity level is closer to 0%. However, the temperature can easily rise up to 110°F in summer. A swamp cooler may decrease the greenhouse temperature but if you’re aiming for much lower, this may not be your best bet.

What features should you look for?

Features to consider before acquiring an evaporative cooling system are based entirely on how you will be using the cooler. Size and air output are the most important factors to be considered.

The following features should serve as guidelines for a decision on the best evaporative coolers for greenhouses.


When looking out for evaporative coolers, you’ll have to consider the size that’ll suit your greenhouse. You have to ensure that the device you intend to get can adequately cool the desired area.

You can get an expert to determine the volume of cooling capacity for your greenhouse per minute or do this yourself. You can do this by checking the size of your greenhouse and using the formula length x width x height. So for example: If you had a MONT 8×12 which is 7.5 ft high in the center, you would end up with 720 cubic feet (8x12x7.5=720). Of course, this assumes the greenhouse is a cuboid, not a house shape but it’s the simple, dirty, overestimating way of calculating it.

Most times, these devices offer a range of cooling capacities for almost every size. There are portable systems with a cooling capacity of 1300 cubic feet (37 cubic meters) per minute that are suitable for most greenhouses.

The maintenance cost

These systems don’t require much maintenance. Just a little work is involved to keep the system going. Each model comes with its own maintenance schedule. Make sure to check that the model you choose has a low maintenance cost.

Additional features

Some features are specific to different evaporative coolers. Some systems are quieter than others. Some have more water capacities and energy-saving features. Make a list of your needs and go for a swamp cooler that is suitable for you.

Before making a purchase, decide which additional features you need the most so you can make a great choice.

How to make your evaporative coolers more effective

To get the best out of your swamp cooler, there are a few tips you can apply.

Regular service

It’s important that you regularly service your cooling system. This improves its effectiveness and makes it last longer. It is advisable to get this done once every six months.

There are a few activities that can help you maintain your cooler. To prevent dirt and dust accumulation, ensure you get your filters cleaned at least every two weeks.

If you have a window cooler, make sure to have the moisture pad changed and the pump cleaned frequently. If not, your cooling pads will become clogged and this will reduce the effectiveness of the device.

These cooling devices are not usually required throughout the year in a greenhouse. So make time to properly clean up the device when you’re done using them for the season.

Remember, a poorly maintained swamp cooler will soon need a replacement!

Scraping away mineral deposits and using inline water filters

Your evaporative cooler requires water to function and water contains certain minerals. So most times, the minerals remain on your cooling system. They form a layer known as a scale.

This can reduce the efficiency of your device. So you must either clean out the scale from your cooling device using a small scraper and a wire brush, or install an in-line water filter (like this one that you can buy on Amazon) to prevent the problem in the first place. These devices can be easily installed and can ultimately be easier to deal with than scraping.

Lubricating the water pump

Normally, there is a pump in your evaporative device that helps the water to flow from the reservoir to the pads. This pump, in addition to being cleaned, needs to be lubricated regularly to help it to operate properly.

Regularly check out the wiring and switches

Once in a while, try to conduct a quick inspection of the system to make sure that all parts are in suitable condition. If you notice any problems, make sure to contact a technician to come and do the repair.

Installing a smart system management device

There are several advanced system management devices that can help you improve the efficiency of your cooler. They are very helpful and reduce stress on you.

The best evaporative coolers for greenhouses

VAGKRI Evaporative Cooler

This amazing evaporative cooling system is great for greenhouses. It is 100% portable since it’s built on casters! You can effortlessly roll it from one area to the other or carry it using the handles. You can trust the VAGKRI Evaporative Cooler to control the temperature of your greenhouse in hot dry weather.

This system works on 120-Volt electricity (145 watts). You can plug it into any electrical outlet and expect the best results. It includes an outstanding 12-gallon reservoir, which will last you for days.

It’ll help you keep regular humidity in your greenhouse. It covers as much as 3000 CMM (Cubic meters/minute).

Portable best evaporative greenhouse cooler blowing cold air out and a remote control next to it
RSI Evaporative Cooler


  • Portable design (on casters)
  • 120° oscillation
  • Large 12 gal tank
  • Remote control with 24h timer
  • Extra large ice packs
  • up to 950 sq.ft.


  • Works most efficiently with ice packs which requires changing them more frequently
  • Water levels may be hard to read

Best for large greenhouses: Hessaire MC37 Evaporative Cooler

This cooling system is one of the most effective in the market. The Hessaire delivers a powerful and compact cooling option, perfect for large areas up to 950 square feet (3100 CFM). It comes with three panels of high-density outlets. You’ll love the simple and compact design.

This choice includes a manual control that helps to adjust temperature settings. This makes it easy to set the temperature to an optimal condition for your plants. Hessaire has multiple units that serve different sized environments.


  • Three-way cooling media that cools areas quickly
  • Portable design
  • Multiple cooling settings
  • Automatically controlled oscillation


  • A bit noisy
  • Plastic body
  • A small amount of assembly required
  • Bulky
Jesse James
Jesse James

Jesse James, a former Army veteran, now shares his passion for gardening through engaging articles on Greenhouse Emporium. Leveraging his experience and love for nature, Jesse provides practical advice and inspires others on their gardening journey.

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