Why Evaporative Cooling Can Sometimes Be the Best Option

There are many reasons to choose evaporative cooling when you’re looking for the best and most efficient way to cool down and keep the heat out during summer.

Among the many benefits of evaporative cooling is that they are cost-effective, eco-friendly and easy to maintain. They are available in two forms – ducted and wall-mounted. With a ducted system the unit will sit on your roof and the entire home – or the rooms you choose – can be cooled as air is delivered through ducts and vents.

A wall-mounted unit is much like a single split system air conditioning unit, in that it will cool one room or a particular area. There are many choices on the market, so let’s examine what makes evaporative cooling an attractive option compared to other air conditioning systems.

How Does an Evaporative Cooler Work?

Evaporative cooling works on the principle of water evaporation through which air is cooled down to provide a comfortable temperature. It is a technique that uses water as a refrigerant.

Evaporative coolers – also known as swamp coolers – are sometimes referred to as air conditioners, but that’s inaccurate. Air conditioners use refrigerant gas, pumps and fans to distribute heated or cooled air, while evaporative coolers use fans, water pumps and cooling pads.

During the process of evaporative cooling, water is evaporated in a stream of air and passes from liquid to gas. This type of transition requires energy, which is extracted from the outside air in the form of heat. The air is cooled as it passes over water-soaked pads, using the natural process of evaporation.

Evaporative cooling can be applied in several ways:

  • Direct evaporative cooling – With this method there is direct contact between the water and the air stream. Water is evaporated directly into the air stream that needs to be cooled.
  • Indirect evaporative cooling – Fresh air enters the system and the air is filtered of dust and allergens. The air is passively cooled before entering the system and the warm air is exhausted from the system. Cool air enters the room with no humidity.
  • Indirect/direct evaporative cooling – This is also known as two-stage evaporative cooling. It uses both indirect and direct techniques to cool the air. As a result, the air can be brought down to a much lower temperature with no humidity.

The Benefits of Evaporative Cooling

An evaporative cooling unit has plenty to offer in terms of affordability and energy efficiency.

These cooling systems also have environmental benefits without the upfront costs of a system powered by solar panels. There are a number of outstanding benefits to choosing an evaporative cooling, so let’s focus on the upside of the system.

Environmental benefits – There’s no doubting how eco-friendly evaporative cooling systems are. They use evaporation for cooling and drive a constant flow of cool air into a warm space, resulting in no greenhouse gas emissions.
Financial benefits – Evaporative cooling systems are cheaper to install and operate than other forms of air conditioning. They cost about 75% less in electricity than conventional AC systems.
Health benefits – The pads are designed to filter the air to trap dust particles and pollen, which is beneficial for people who suffer from allergies.
Keep your windows open – Unlike other forms of air conditioning, windows and doors can be left open with an evaporative cooling system. In fact, it is recommended, otherwise the air might get too humid. This way the unit constantly cycles fresh, clean air into your home.
Low maintenance – Evaporative coolers are low maintenance due to their simple design.

When is Evaporative Cooling Not the Best Option?

As good as evaporative cooling is in most ways, there are some drawbacks to the system.

A conventional air conditioning unit could be preferable in some circumstances. Here are some of the cons to consider with evaporative cooling:

  • It requires a continual water source to run efficiently, using up to 25 litres of water per hour in humid conditions.
  • It needs regular cleaning to alleviate bacteria and mould.
  • An evaporative cooler is not a good choice for wet/humid climates.
  • An evaporative system is cooling only.
  • Water leakage from ceiling units can occur.
  • Noise from an evaporative cooler can bother neighbours.
  • While they are low maintenance, services can be expensive. Units should be checked every two years.
  • Evaporative cooling systems are not so effective for large houses. Cool air won’t be distributed throughout the entire home. They are more suited to cooling down one room.
  • Evaporative coolers don’t have thermostats to set the desired temperature. However, the fan speed can be adjusted to increase or reduce the airflow.

Making the Best Choice

Knowing the difference between evaporative systems and other kinds of air conditioners is the key to making the right choice for your household.

If you live in a dry climate and you’re looking for a cooling system that is eco-friendly, cost-effective and energy efficient, it’s hard not to consider evaporative cooling. However, if you want more exact climate control and wish to reduce humidity, a reverse cycle air conditioner may be preferable to evaporative cooling.

Always consult an air conditioning specialist for advice and installation. Not only is it the best way to get the most out of your new unit, but you’ll also avoid problems down the track caused by poor installation (which may possibly void the warranty).

Please note: This information is provided for advice purposes only. Regulations differ from state to state, so please consult your local authorities or an industry professional before proceeding with any work. See our Terms & Conditions here.


Last Edited on: 9th November 2022