How Does An Evaporative Cooler Do Its Job?

Also known as swamp cooler, wet air cooler, or sometimes a desert cooler, the evaporative cooler is slowly becoming a popular alternative to conventional home-cooling methods such as air conditioners due to various reasons, including energy efficiency. As the name suggests, this is a device that cools air through the means of evaporation. Evaporative coolers have been proven to provide efficient cooling, especially in hot dry conditions rather than in humid conditions. This is because the system relies on evaporating the moisture from the wet filter pads to provide the cooling effect needed.

In this article on how does an evaporative cooler work? We are going to tackle one key factor that is mainly exploited, enthalpy of vaporization, which can be described as the amount of energy required to transform a liquid substance into gas. In this case, water is basically our liquid substance.

Simple Mechanical Principles

The human body is a classic best example when it comes to explaining how evaporative cooling works. The moisture on our skin surface, also known as perspiration, once into contact with the air, evaporates leaving us with a cool sensation. It is this process of evaporation that cools the skin hence lowering our body temperatures.

In evaporative coolers, a fan inside the unit is used to draw the outside air and passes it through a set of wet filter pads. When hot air passes through these wet filter pads, impurities are removed and the air cooled. After the hot air has been cooled, the wet filter pads retain the warmth. The warm water inside the filter pads trickles down and is replaced by cool water pumped to the top of the pads, in a continuous cycle. A tank at the base of the unit contains the required amount of water needed to ensure this cycle goes on.

Before proceeding with evaporative cooler installation, make sure ample ventilation is necessary because the cool air is not re-circulated in the building. This means that you may need to open your doors or windows to allow the already the indoor air to escape the building. However, for security reasons, installation of up ducts with the provision of attic ventilation is necessary to ensure that warm air is exhausted into the attic as cool air comes in from the evaporative cooler.

Maximizing on Performance

Setting the correct number of window openings is paramount as far as performance is concerned. Once the cool air is blown into the room from the evaporative cooler, it needs to be let out or else fresh air won’t be able to get in. Keeping your windows open or alternatively installing up ducts will be your best option when it comes to getting the best of performance from your evaporative cooler. Basically, you will need 300mm window opening for each and every room, which may vary depending on the room size. Your home’s location matters a lot because the evaporative cooler opening should not face the wind. Proper maintenance is also overly important and you can ensure this by having the cooler serviced at least two times annually.

Proper Sizing

Air flow and the space of the area in need of cooling are the determinant factors that affect the size of evaporative cooler you want to install. Getting the accurate quotation from your retailer and having your installer do some humidity tests are important tasks that need undertaking.
An evaporative cooler not only cools your home, they also add some pleasant moisture in it and will not circulate the air inside over and over but will bring in fresh air from outside, and it is up to you to ensure the necessary ventilation.


Categories: Heating and Cooling