young woman relaxing on lounge under evaporative cooling system

How Does Evaporative Cooling Work?

Finding the right cooling solution for your home becomes crucial as temperatures rise and the sun beats down. Have you ever wondered how evaporative cooling, sometimes known as a “swamp cooler,” keeps you cool in the summer? 

In this article, we’ll break it down in simple terms. We’ll explain the basics, uncover the system’s components, dive into the benefits, talk about common issues and how to fix them, and even help you choose the right cooler for your home. 

Read on to find out how this eco-friendly and budget-friendly cooling method keeps you chill during scorching days.

how evaporative cooling works

How Evaporative Cooling Works – The Basics

The technique of cooling air by evaporation is known as evaporative cooling. To do this, a cooling unit mounted on the roof is connected to a network of outlets, or ducts, strategically located throughout the structure, bringing in the surrounding fresh, humid, or cool air from the outdoors. 

As the heated air passes through the wet pads or quilts, it is cooled, and its moisture content is increased due to evaporation. With this method, evaporative coolers can be employed in outdoor settings.

Basically, it draws in hot air from the outdoors, cools it, and then distributes it around the house via the duct system, cooling the spaces that need it and expelling the rest through the open windows and doors.


Installing an evaporative cooler can be done in two ways: cool air from an evaporative cooler can be directed to one specific place, or it can be piped throughout the building via a duct system. Smaller homes with an open floor plan can benefit from centralised installations, whereas larger residences with halls and several rooms require ducted systems.

Most homes have their evaporative coolers set up in a down-flow configuration on the roof.  Many experts, however, opt for ground-mounted horizontal units, which are easier to maintain and pose less of a risk of roof leaks.


You should be able to choose between two speeds and a vent-only setting on an evaporative cooler. In vent-only mode, the water pump is turned off, so the air outside is not humidified. This enables you to utilise the evaporative cooler as a ventilation during mild weathers.

By opening windows in the rooms you wish to cool and closing them in the rooms that are empty, you can control the temperature and humidity in the room. In areas where people leaving their windows open could compromise safety, up-ducts could be installed. 

When the evaporative cooler kicks on, the up-ducts release hot air into the attic and bring in cooler air. Up-ducted evaporative coolers necessitate supplementary attic ventilation.

Homeowners with allergies may prefer filters that remove most airborne dust. Filters can also prevent some coolers from pulling water droplets from pads into fan blades. Few evaporative coolers come with air filters, although they can be added during or after installation.

Components of an Evaporative Cooling System

There are several essential parts to an evaporative cooling system, and they all work together to accomplish the cooling goal.

  • Water Reservoir: The water for the cooling pad is collected in a reservoir and then pumped out to the pads as needed.
  • Pump: The pump is responsible for re-supplying the cooling pad with water from the reservoir.
  • Cooling Pad: Made of absorbent material, the cooling pad holds water and assists the cooling process.
  • Fan: The fan blows hot air out of your home and through the cooling pad.
young woman relaxing on lounge under evaporative cooling system

The Benefits of Evaporative Cooling

Economical And Environmentally Friendly

When compared to conventional air conditioning, evaporative cooling has many advantages. Because of its structure, it consumes considerably less energy on an hourly basis. As a result, you’ll be able to save more money on your utility bills, which is good for your wallet and the planet. 

Evaporative coolers, in contrast to central air conditioning, don’t use Chlorofluorocarbons, hence they don’t contribute to the supposed depletion of the ozone layer. It’s also easier to use, less complicated, and more applicable in places with dry, hot climates.

Healthier Option

Evaporative cooling provides healthier, cleaner air than air conditioning because it does not recirculate air. This is in contrast to the effects of air conditioning, which can be irritating to the eyes of those who are sensitive to dry air. 

In addition, stagnant air in your residence is substituted with fresh air. Because of this, people with respiratory conditions like asthma and allergies typically prefer evaporative cooling systems to central air conditioning.

Evaporative cooling is preferred over air conditioning in Australia for several reasons, including the fact that doors and windows are typically left open all year round. Turning on the fans in the winter is a terrific method to eliminate the stale air that builds up within the house throughout the colder months.

electrician installing evaporative cooler

Common Issues and Troubleshooting

Even though evaporative cooling works well and saves money, it can run into some problems. These include poor cooling, odours, limited airflow, water leaks, humidity, noise, uneven cooling, electrical issues, and regular maintenance. 

Checking cooling pads, water pumps, leaks, humidity, noise, and electrical faults can help address these issues. 

In the summer, regular maintenance and troubleshooting can keep your evaporative cooler running smoothly.  Professional inspection and maintenance may be needed if issues continue.

Humid regions are not ideal for evaporative cooler use since they increase indoor humidity. Furthermore, they do not provide as much cooling as an air conditioner and need easy maintenance often. 

Maintenance visits for an evaporative cooler put on the roof can cause the roof to deteriorate over time. A rooftop cooler that is in the sun will not cool as well as one that is in the shade. It can be inconvenient to have to use a ladder to access the roof for repairs.

Evaporative coolers, by their very design, require a constant water supply. Homeowners in areas with low water pressure may think twice about installing an evaporative cooler.

woman controlling the temperature in her home with a smart device

Choosing the Right Evaporative Cooler for Your Home

The best evaporative cooling system relies on climate, running costs, size, and water usage. Here, we’ll discuss these systems’ ideal settings, operating costs, size and selection, and how water use affects decision-making.

The Ideal Setting

Depending on the ambient temperature and humidity, evaporative cooling systems can have a wide range of efficiencies and effectivenesses. Because of its reliance on evaporation from a wet filter pad, evaporative cooling systems are inefficient in humid or extremely hot climates and can only cool the air to a certain degree. 

Hot, dry climates are ideal for their use. Humid air outside reduces the cooling capacity of the device because water cannot evaporate as readily from the pads. 

Operating Expenses

Electricity and water are required to power an evaporative cooler. Actual running expenses will depend on the cooling capability of the device and the fan speed that you set. It is impossible to compare evaporative cooler models because they are not required to carry efficiency labels.

Size and Selection

The amount of air that can be delivered to a residence by an evaporative cooler is measured in cubic feet per minute (CFM). Most standard models have a range between 3000 and 25000 CFM. Depending on local weather conditions, manufacturers suggest installing fans capable of 20-40 air changes per hour.

Water Consumption

Electricity and water are required to power an evaporative cooler. How much water is utilised is based on several factors, including the unit’s size, the relative humidity, and the fan speed.

Different types and kinds of ducted evaporative coolers employ varying water management technologies to ensure that the water supply is regularly refreshed and never becomes excessively salty.

Before buying a ducted swamp cooler, ask about its water management system and local hourly water use. It is more cost-effective to use a refrigerative cooling system if solar panels are installed on your roof, as the water expenses of evaporative cooling will probably outweigh any energy savings.


If you’re looking to battle the heat and make your home more pleasant without breaking the bank, evaporative conditioning is the way to go. You can make a smart choice regarding your cooling needs with the knowledge of how evaporative cooling functions and its advantages. 

Evaporative cooling could be the answer to your hot summer days if you live in a dry region or if you just want an energy-efficient solution. Don’t allow the heat get the best of you; instead, utilise evaporative cooling to keep cool and comfortable.

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