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What is Evaporative Cooling?


Evaporative coolers are a form of air conditioning that is quite popular in hot and dry climates. They are seen as an efficient and eco-friendly cooling solution over conventional air conditioners. This is for a number of reasons but mostly because they usually use less power than regular air conditioners and generally cost less to run as a result.

Wet Foggy Glass

How does evaporative cooling work?

Evaporative cooling systems work by dragging hot, dry outdoor air through wet filter pads before distributing it through the house. Cool air is created as hot air is pushed through these pads and the heat evaporates the water. The result is cool and humid air that is distributed around the house using a series of ducts and vents. This process is different from more normal air conditioners which work by cooling the air already in your home using gases and chemicals. As a result, traditional air conditioners need more energy to operate and produce more carbon dioxide. Evaporative cooling introduces fresh air into your home and relies on the passive process of evaporation to keep you cool.

Is evaporative cooling good?

Evaporative coolers are very good at what they are made for. They are efficient systems that introduce cool and damp air into your house without a lot of energy use or greenhouse gas emissions. However, there are some limitations that you should be aware of in order to get the most out of your system.

The system needs a regular supply of water to keep the filter pads damp at all times. If the pads are not wet enough then the air that is drawn inside won’t be cooled sufficiently to have an effect. As a result, evaporative coolers will need a fair amount of water to operate.

Additionally, windows need to be left open to keep the system working properly. This is because open windows will let the hot inside air out and provide the ventilation you need to keep air moving around the house. This is where Solar Whiz can be of use to you and your system. Read on to find out more!

Evaporative coolers work best in hot and dry climates. They are far less effective in humid environments because water can’t evaporate from the pads as easily. For example, Sustainability Victoria says that Melbourne’s humidity during summer is usually 40-50%, compared to 20-30% in Mildura. Clearly, an evaporative cooler would have a much better impact on homes in Mildura. This shows how performance can be limited as the humidity levels increase.

However, increasing humidity and moisture in your home can be bad without enough ventilation. Damp and moist conditions can warp wooden structures and are the perfect breeding ground for mould. We have a page talking more about moisture and condensation here.

solar attic fan installed in a tin roof

How Does Solar Whiz Help Evaporative Coolers?

Solar Whiz is not an evaporative cooler. Our solar powered fans are powerful solar extraction and ventilation units. They work by extracting inside air and replacing it with fresher, cooler, and drier outdoor air.

It might seem counter-intuitive to install a Solar Whiz when you have an evaporative cooler. Solar Whiz is designed to extract indoor air and replace it with fresher, cooler, and (most often) drier air from outside. Compare this to the evaporative cooling system that draws in hotter and drier air and deliberately cools and moistens it. However, although evaporative coolers are great in dry conditions, their performance suffers greatly when humidity increases.

Solar Whiz will work well with an evaporative cooler in places where it is mostly dry, but can sometimes be humid. For example, Victoria is generally considered to have a drier climate compared to more northern states. Evaporative coolers can perform much better in Victoria as a result. This is why Queensland and Sydney homes will rarely ever need or use an evaporative cooler. However, hot and humid summers do happen every now and then. When this happens an evaporative cooling system will be of no help at all. It could actually be doing more harm by introducing excessive moisture to your home. That is why Solar whiz units are great at helping evaporative coolers stay effective by removing the moisture they introduce. Our units will extract the unnecessary moisture, letting your cooling system continue to provide you with cool air.

Solar Whiz helps to improve the efficiency of an evaporative cooling system, just like it helps improve the efficiency of conventional air conditioners. Contact us today to find out more about how we can suit a Solar Whiz to your specific needs!

solar powered fans

Frequently Asked Questions

What are evaporative coolers?

Evaporative air coolers, also called swamp coolers, are a type of air conditioner that works by harnessing the power of evaporation to cool air temperatures.

How does evaporative cooling work?

Evaporative coolers draw warm air from outside through wet filter pads supplied with water from a reservoir at the bottom of the unit. The water evaporates from the filter pads, draws heat from the air and humidifies it. Cooled moist air is then blown through the house.

Are evaporative coolers good?

Evaporative coolers are most effective in hot, dry climates with low humidity because the air has a greater capacity to absorb water vapour. They are not recommended for use in humid or wet climates. They depend on a reliable water supply.

Do evaporative coolers increase humidity?

Evaporative air coolers blow out cooler, more humid air, which constantly increases the humidity in the room.

Do evaporative coolers work in high humidity?

Evaporative cooling works well in hot, dry climates where humidity is typically below 25% on hot summer days. Evaporative coolers work under higher humidity conditions, especially when the ambient temperature is cooler, but often require more airflow to achieve satisfactory cooling.