How Much Does It Cost to Run an Evaporative Cooler? How Many Watts Does It Use?

Evaporative coolers, also known as swamp coolers, are air conditioning appliances that use the principle of evaporation.

Using water, pads and a blower to provide cool air, they have become a popular household item in moderate climates with low to medium humidity, but are not suitable for areas with high humidity.

This is because they also add moisture to the air which can raise the humidity level to unmanageable points. As long as you understand this point, you shouldn’t have a problem using one of these cooling units.

Evaporative coolers won’t provide as much cooling as air conditioners do, but they sure won’t require as much to run. But, just how much does it cost to run an evaporative cooler?

We can tell you for free that it depends on a number of factors, including the size and wattage of the unit, how long it runs, and how much work it is expected to do.

However, we’ll attempt to provide a comprehensive analysis of how much a typical evaporative cooler will cost to run, just in case you’re considering adding one to your HVAC collection.

Do Swamp Coolers Use a Lot of Electricity?

No, swamp coolers do not use a lot of electricity. Compared to what? You may ask. Ideally, swamp coolers are purchased to act as an alternative cooling appliance to air conditioners and they use far less electricity.

The reason is simple; the only component that really needs electricity in a swamp cooler is the fan which blows out cool water vapor from the water pad in the unit. Ordinarily, fans do not need that much electricity to run and that explains the low electricity demands of evaporative coolers.

Unlike the AC which has several components like the condensing unit, fan unit, compressor unit, and other components working at the same time to cool your room, a swamp cooler only has a fan.

The other major components like the water reservoir and the water pad do not run on electricity.

Even among swamp coolers, there are larger units that may cost more to run than smaller units. Be sure to get the exact size you need, and you should also check the energy efficiency of the unit.

Top 3 Most Energy Efficient Evaporative Coolers

1. Hessaire MC37M Evaporative Cooler
2. AOLOS 3-in-1 Evaporative Air Cooler
3. Honeywell Home CS071AE Low Energy Portable Evaporative Cooler

How Many Watts Does an Evaporative Cooler Use?

The wattage of an evaporative cooler depends on its size and capacity. The technology and energy efficiency of its design can also determine how much wattage a unit uses.

Generally, evaporative coolers use between 100 watts and 500 watts. It all depends on the capacity and size of the actual unit.

More often than not, the wattage of the unit you intend to buy will be stated on the package or product description online. If you do not find it there, take a look at the information plate on the fan motor.

At 100W-500W, this is much less energy consumption than a typical air conditioner.

Sometimes, you may get a unit with an incredibly small fan that may only use up less than 100 watts, such as the AGILLY 3-in-1 evaporative cooler; the same way you can get a big capacity fan that may require as much as 500 watts. But you’ll find that most units are within the 100W to 500W range.

How Often Should Evaporative Cooler Pads Be Changed?

Every 3-5 years on average. This depends on a number of factors, including how often you use the appliance and the quality of water in your home.

If the water in your home is hard or highly mineralized, it is likely to leave mineral residue on the pad which may cause clogging or cause it to rust quicker than normal.

On the other hand, extensive usage will cause the pad to diminish faster and you may need to replace it sooner than usual. This is why it is important to use a water softening system in your home and only demineralized water for your swamp cooler.

An evaporative cooler pad is a water-absorbing component in the unit that soaks up water and which the fan blows over to release water vapor into the room. Without this pad, your swamp cooler is more or less a fan with a water tank.

How Often Do You Need to Change the Filter on A Swamp Cooler?

At least once a month. This is only important for swamp coolers that are built with filters. Some evaporative coolers come with filters for some level of air purification.

This filter helps to trap dust and pollutants which pass through the air cooler, ensuring that only clean air returns to the room.

Just like those used in air purifiers, these filters would need to be changed regularly if they are not washable and reusable. You should be ready to replace them every 30 days for continued air purification.

Failure to do this may lead to severe allergies and respiratory infections. It is also important to know that a functional filter helps to keep the unit working optimally and prevents clogging.

How Much Does It Cost to Run an Evaporative Cooler?

Therefore, a 400-watt swamp cooler can be calculated for running cost using the formula below;

400 ÷ 1,000 (to arrive at kilowatt) x 13

That is, 0.4 x 13 = 5.2 cents ($0.052) per hour.

If you run the unit for 12 hours daily, that will amount to $0.052 x 12, which equals $0.624 per day, and $18.72 per month.

As for replacement pads, you’ll get them for an average of $25 per unit, while the replacement filter will cost between $15 and $25 each. These prices also vary according to size and brand.

Let’s consider the average running cost for some swamp cooler sizes:

	Electricity Cost/Month	Replacement Filter	Replacement Pad
Extra Large, 1,200+ sq ft, 6-8 gallon 250-500 watt swamp coolers	$15 to $20 per month	$25 per month and about $1,500 over a period of 5 years.	$25 for every 3 years; $50 over the lifespan of the unit.
Large 700 sq ft, 5-gallon, 100-300 watt swamp coolers	$10 to $15 per month	$25 per month and about $1,500 over a period of 5 years.	$25 for every 3 years; $50 over the lifespan of the unit
Medium 350-600 sq ft, 3-5 gallon, 80-150 watt swamp coolers	$7 to $12 per month	$20 per month and about $1,200 over a period of 5 years.	$25 for every 3 years; $50 over the lifespan of the unit.
Small 100-300 sq ft, 1-3 gallon, 50-80 watt swamp coolers.	$2 to $5 per month	$15 per month and about $900 over a period of 5 years.	$25 for every 3 years; $50 over the lifespan of the unit.

Note that the costs highlighted in the table above are based on standard usage and do not take into consideration variations in duration of usage or extreme circumstances like using hard or mineralized water.

You should also know that most evaporative coolers do not come with filters and use the water pad as its filter and that will also affect the running cost.

Which Are the Most Economical Evaporative Coolers?

As per our research, we found below 3 evaporative coolers consume less energy and hence, very economical.

Final Words:

As we’ve shown in this post, it doesn’t cost that much to run an evaporative cooler, especially one that doesn’t use a filter. They are more affordable than air conditioners, are great for hot and dry regions because of their humidifying quality and are cheaper to run due to lower wattage.

The products listed above are some of the most economical you’ll find as a result of their wattage per output and coverage.

If they don’t fit into your preference, you can choose from the many other brands available; just be sure to check their square footage, water gallon capacity and wattage.