Why do fans cool us?

Fans do not generate cold air, but instead cool us by the displacement of the air around us.

What is this effect due to?

More than one will be familiar with the question that has sometimes been asked to test people’s knowledge of physics:

What would happen to the temperature of a closed room if we left a fan running?

Well the answer is clear:

Quite contrary to what many may think, this would heat up .

Even disregarding the heat that the motor that turns the blades can produce, the fact of circulating the air generates friction between its molecules and this raises the temperature of the myself.

So if they don’t cool the air, why do fans cool us?

In most cases we do not start from a completely closed room, or at least it should not be this way since we need the air to circulate and be distributed throughout the rest of the house.

The air around us is saturated with humidity due to the evaporation of sweat that we generate through perspiration.

By displacing this air, it is replaced by a drier one that can absorb the water vapor that we give off and therefore make us feel fresher.

This is the explanation why fans cool us even if they cool the air.

Why do we use a fan to cool off?

When it is hot or we have done physical exercise, the body eliminates excess heat through perspiration.

In the process, water is expelled that accumulates on the skin creating a film of moisture that prevents perspiration and, therefore, we are unable to remove excess heat correctly.

If we use a fan, by circulating the air, we manage to eliminate the aforementioned moisture film by reactivating perspiration and thus lowering our body temperature.

What is thermal sensation?

The concept will already sound familiar to us; When meteorologists give us the temperature, it is usually accompanied by the data of the thermal sensation, which is the degree of comfort, a mixture of the temperature and the degree of humidity of the environment.

The thermal sensation is linked to the level of humidity in the air and consequently its ability to absorb the excess heat that our body eliminates in the form of sweat.

If it is very hot and we live near the sea, rivers or swamps, the thermal sensation is higher, this is because the water in them heats up and evaporates, resulting in the air being loaded with humidity.

Heat is associated with increased humidity in the environment

We all know the water cycle that begins with the heat of the sun over an area of water, whether in the sea, lake or swamp, and the evaporation of this ends up forming clouds that when cooled in the upper layers of the atmosphere will precipitate in the form of rain to filter into the ground and reach the areas where the cycle started again by rivers.

In the process of evaporation, the humidity in the environment increases and the more saturated with humidity it is, the less capacity it has to absorb the excess steam that we generate.

Likewise, the principle that applies to a fan inside our houses is the one that applies when we hang our clothes and the air that runs dry.

Clothes dry due to the displacement of air saturated with the humidity generated by it and that exists around it, leaving room for drier air that absorbs this vapor.

Fresh air fans

Now we know why fans that only have propellers to move the air cool us, but we must not forget that over time fans have appeared that thanks to new mechanisms, such as the Bernoulli effect , they achieve a channeling of the air that generates much greater and better directed currents, giving a greater sensation of freshness.

Perhaps the best known brand for being the first to use this technology is Dyson although today there are a lot of brands that offer fans of this type.

If you don’t want to be hot this summer, get a good fan

Before the heat catches you off guard, take action and get a good fan to cool off at home and better spend those hours of the day when not even the lizards come out.

Check our fan sections, you have all kinds:

Tower fans when space is an issue.

Bladeless fans for designer ventilation.

Bladeless ceiling fans to add a touch of style as well as cooling.

Standing fans to ventilate more space.

Industrial fans for warehouses, gyms and large spaces that must be ventilated.

Misting fans to create a cool breeze.

Table fans to cool you where you need it.

Ceiling fans to have ventilation at any time in our favorite place.

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