Swamp coolers, also known as evaporative air coolers, are the most efficient and energy-saving devices for personal cooling. Portable, minimalist and eco-friendly, they are a fantastic cooling option for rentals, vans, even tents or dog houses!

In this article, we will calculate the size of the swamp cooler, so you will know how to choose the right size for you.



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What size evaporative air cooler do I need?

Unfortunately, it is easy to get lost among all the models when deciding on the evaporative cooler sizing.

Swamp cooler sizing differs from picking the air conditioner size because the devices serve a different purpose and use other cooling methods. Also, air conditioners use BTU (British Thermal Units) to measure cooling capacity, while air coolers work with CFM (Cubic Feet per Minute).

However, it is common to see both units on evaporative coolers, so we made an evaporative cooler size guide taking into account both.

While evaporative air coolers and swamp coolers use the exact cooling method, the usual difference is the size of the unit. The term ‘evaporative cooler’ is commonly used for smaller models, and ‘swamp cooler’ is for a device that cools larger surfaces. These two terms are interchangeable most of the time.

For convenience, we will use both terms to help you decide on the swamp cooler sizes based on your needs. Then, we will dive into more detail with dimensions, installation requirements, CFM, and cooling power.

What size swamp cooler do I need?

The evaporative cooler size you pick will depend on the following criteria.

1.   Humidity

We wanted to start with this one because humidity levels in the room you need to cool will define the final efficiency of your device. Swamp coolers work best in dry climates because they use evaporation for cooling.

2.   Insulation

A poorly insulated place will require more energy from a swamp cooler than a place with solid insulation.


3.   Size of the space you need to cool

Specific evaporative cooling formulas apply to the sizing of evaporative coolers, given regular ceilings height. Therefore, you will need the size of the space that you need to cool and the height of the ceiling to pick the correct swamp cooler size.

4.   Personal requirements

A lot of the evaporative cooler sizing will depend on how precisely you use the cooler. For example, there is a big difference in sizing depending on whether you need to cool down the entire room or if you want to cool the personal space.

The evaporative cooling sizing will also depend on your activity within the space — the cooling needs will differ between working out or simply chilling with a book. Read also: Do Swamp Coolers Actually Work?

Evaporative Cooler Size Calculator

The usual formula to calculate the swamp cooler size is the following:

Square feet needed to be cooled X ceiling height (in feet).

You divide it by two, and this quotient is how many swamp cooler CFM you will want.

We would like to be precise that most swamp coolers and evaporative coolers are designed to cool down your personal area efficiently. However, if you are more interested in a cooling device for the whole room, you can also check out our article on the size of an air conditioner for your place.

You can also measure the evaporative cooling potential in BTUs. It won’t be as precise as it is for air conditioners. However, it is also a commonly used unit and can be helpful as a general guideline. Thus, the swamp cooler size calculator helps you make the right choice.

Swamp cooler sizing chart in BTU

When sizing your evaporative cooler, make sure you also consider the ceiling height. If you are looking for a swamp cooler for the whole place and not just your personal cooling, the global rule is that an ideal evaporative cooler can replace the indoor air in under 2 minutes. This is where all the above calculations come in handy.

Recommendations and tips for different rooms and occasions

The evaporative cooler sizes and types will also depend on how and where you plan to use them.

  • Large windowless spaces such as warehouses and manufacturing facilities

If these places don’t have a window, you will need the strongest portable evaporative air coolers that don’t need the outdoor air to function. We recommend you consult a professional to ensure your industrial facility is suitable for a swamp cooling system.

  • Relatively large homes and workshops with windows

Window evaporative coolers are usually used in homes and workshops and can be easily stored during the winter months.

  • Whole building

You might need to install several air coolers or a ducted cooling system. The latter requires installation work, making it a more solid option when you own the place.

  • Personal cooling

Swamp coolers are the best option when it comes to your personal cooling. Whether you are working out, focusing on a deadline, or chilling with your favorite book, you simply need a small portable evaporative air cooler for a flow of fresh air. Evapolar air coolers are the best solutions in the world of personal cooling. Direct the flow from the grill at you and enjoy the most efficient, eco-friendly, gentle breeze.

Evaporative air coolers use way less energy than traditional air conditioners. On top of that, they are environmentally friendly. Choosing the best evaporative air cooler like Evapolar as your cooling solution can help save money on electricity and help keep the environment clean while keeping your personal space fresh and comfortable.

Evapolar doesn’t need any complex calculations to size the cooler because they focus on individual spot cooling. They direct all their efficiency at you, making your space cool and comfy. On top of that, there are many ways to boost your personal swamp cooler and make it work even better. They have also been voted the best cooling devices for remote work — check out for yourself!

People also ask (FAQ):

1. What is the difference between a swamp cooler and an evaporative air cooler?

Mostly, the difference is only in the name since both these types of coolers use evaporation as a cooling method. However, most commonly, people search for swamp coolers to cool larger areas and evaporative air coolers when they need personal cooling.

2. What is the difference between swamp coolers and air conditioners?

The difference is in the cooling method. Air conditioners use the hot air from the outside to turn it into cool air, while swamp coolers use evaporation. So, for example, air-cons need to work with closed windows only, and air coolers work even better with open windows.

3. Which one is cheaper to run, an evaporative air cooler or an air conditioner?

Evaporative air coolers are the most efficient, energy-saving cooling method. You can see in our recent article how they compare to air conditioners. A ducted evaporative air cooler consumes 50% less energy than a ducted air con. Evapolar air coolers are the most eco-friendly and energy-saving models for personal cooling today.

4. Are evaporative air coolers eco-friendly?

Yes, evaporative air coolers are the most eco-friendly cooling method. First, evaporation is cooling as nature has invented. Second, they use very little energy and have the smallest environmental impact compared to most cooling devices.

5. What is the ideal humidity for the evaporative air coolers to be the most efficient?

A swamp cooler is a ‘Yes’ for you if you live in a dry climate. Evaporative coolers for residential use work best with the dew point below 50°F.