Ceiling fans are one of the most useful home appliances, beneficial to you all year round. A ceiling fan can provide a cooling or warming effect in the room depending on the direction in which its blades spin.
As this direction is changeable and almost no fans have the winter/summer mode switch labeled, it is helpful to be able to tell the difference between the two based on the fan operation.
In summer, ceiling fan blades should rotate counterclockwise as viewed from directly below the fan. In this direction, the blade is angled to cut through the air and push it down over those below the fan. This is necessary as wind chill from airflow over skin is how a ceiling fan cools a person.
Should Ceiling Fan Be Blowing up or Down in Summer?
The cooling effect of a ceiling fan is dependent on the movement of air over our skin (which is why there’s no point in running a ceiling fan in an empty room), so in summer mode, the ceiling fan should be blowing down. This downward movement of air should be perceptible directly below the fan, even on the lowest setting.
Ceiling Fan Cooling Mechanism
Ceiling fans do not remove heat energy from the air as an AC does. They have no components capable of this, yet they are effective at cooling people and have been successfully doing so for decades. So, how do they actually work?
Ceiling fans in summer mode rely on airflow to cause something known as convection cooling or wind chill. You experience this outside on a hot day when a breeze picks up and blows past you.
Wind chill is when the layer of heated air trapped against our skin is blown away by air currents. More of our body heat escapes into this space only to be blown away again.
In this way, our body temperatures drop even though the fan lacks the ability to cool the actual air temperature.
The faster the fan’s blades spin, the faster air circulates downward to cool your skin and make you feel comfortable during the summer heat.
Counterclockwise Spinning Provides Cooling
In summer, your fan will be spinning counterclockwise to produce the downward flow of air. Looking at a fan from the side makes determining the rotational direction a bit difficult. So, in order to tell if your fan is spinning counterclockwise, you will need to put it on the lowest setting, stand directly beneath it, and look up.
From this angle, it should be moving from right to left and the highest point of the pitched blades should be leading, cutting through the air and forcing it down.
If you are witnessing your fan moving in a counterclockwise direction but you don’t feel any air blowing over you, then double check the blade pitch. It may be reversed. This is not a bad thing; you will just have a fan that is in summer mode when the blades are rotating clockwise.
Using the ceiling fan in summer mode in addition to the AC can make both systems more efficient and more energy-efficient.
You can also start taking advantage of the ceiling fan’s summer mode rotation as soon as spring temperatures start to rise.
Sources
https://saveonenergy.ca/For-Your-Home/Advice-and-Tips/Seasonal-ceiling-fan-direction
https://www.rsbelectricalinc.com/blog/2017/9/11/how-cailing-fans-work-in-summer-and-winter
https://blog.ceilingfan.com/5-factors-that-determine-ceiling-fan-airflow/
https://www.sparkenergy.com/ceiling-fan-direction-can-save-energy/
https://www.hansenwholesale.com/ceiling-fans/fan-direction-summer-winter