A ceiling fan can run in two directions; clockwise and counter-clockwise. All ceiling fans run counter-clockwise by default. But you can reverse the direction of most fans by flipping a switch on its motor housing.
This two-directional running is implemented to make a ceiling fan usable during the winter and summer seasons. Even though ceiling fans are widely used to cool down a room during the hot summer days, you can also use them to warm up a room by reversing its direction of spin.
A ceiling fan should spin in the counter-clockwise direction during summer and in the clockwise direction during winter. These spinning directions are based on which way the fan spins when you look at it from below.
To learn more on how a fan’s spinning direction affects a room, read the rest of this article.
Which way should a ceiling fan spin in the summer?
Summer is when I need a cool breeze flowing through my living room. When it is hot, I switch on my fan and it instantly cools me down. But what direction is it running?
In the summer, a ceiling fan should spin in the counter-clockwise direction when viewed from below. Spinning in this direction generates a strong downward breeze that creates a wind-chill effect, cooling down everyone under the fan.
But why should it turn only in the counter-clock direction, why can’t push down air when running the other way?
This is because the ceiling fan blades are generally pitched (made at an angle) to create downward air movement only when the fan turns in the counter-clockwise direction.
Let me explain this a little further. The blades of the ceiling fan are fitted at a small angle with a horizontal plane. It is due to this angle that the blades are able to move air. Universally for ceiling fans, this angle is sloped towards the right. That is, the cross-section of a ceiling fan blade, when looked at from outwards, will be slightly raised on its left. Due to this design, these blades can move air downwards only if the fan runs in the anti-clockwise direction.
When the fan runs in the counter-clockwise direction, these angled blades push the air in their way downwards towards anyone sitting under it. This creates a breeze that carries away the heat from our bodies. This body heat dissipation creates a cooling effect on us. This cooling effect increases with the increase in the fan speed. A regular ceiling fan can make the room feel cooler by up to 4 degree Celcius.
If the fan rotates the other way, it will only pull the air up. So you won’t feel any air movement even if you are sitting directly under it.
Direction of ceiling fan for winter
Nobody wants to feel the chill effect of a ceiling fan during the cold winter months. However, you can use it to distribute the heat inside a room evenly. What in what direction should it turn for this?
A ceiling fan should spin in the clockwise direction during the cold winter months. This causes the air to flow upwards towards the ceiling. This helps to recirculate the hot air trapped near the ceiling thus effectively warming up the room.
Need more explanation? Here we go;
As you know, hot air rises. During winter, even though the room heaters heat the room, most of the hot air will be trapped near the ceiling thanks to convection. This means the effective temperature at the living heights stays low, tending the occupants to turn up the thermostat.
But if you can recirculate the hot air trapped near the ceiling, isn’t that more economical and efficient? This is exactly what a ceiling fan does once its spin is reversed.
When a ceiling fan runs in the clockwise direction when viewed from below, the angle of its blades causes the air to move up. Simply put, the fan blows the air upwards instead of downwards. This pushes the hot air near the ceiling outwards and onto the occupants below, thus increasing the room’s warmth.
But here is a good question; why can’t the fan recirculate hot air when it blows downwards?
This is because of two reasons; wind chill effect and heat transfer rate.
Wind chill effect is the cooling effect felt by you when a fan blows over you. This is because the fast-moving air removes the hot air in your vicinity, making you feel cooler. This works just like how sweating makes you feel cool. This chill effect happens at all temperatures. So, even if the fan is blowing hot air onto you, you won’t feel its full hotness because of this effect.
But a fan running clockwise doesn’t create this downdraft, and hence there is no wind chill effect. But it warms up the room nevertheless. So this is one reason why the ceiling fan is run clockwise in the winter.
The second reason for running the fan clockwise is the heat transfer rate. When the hot air stays near the ceiling, the ceiling absorbs some heat. When cool air moves upwards, it absorbs some of this heat back and circulates it throughout the room. Since a fan running clockwise blows up cool air, the rate at which the heat is absorbed from the ceiling is higher. If the fan were running counter-clockwise, it wouldn’t be able to absorb this much heat from the ceiling due to the low air velocity near the ceiling.
How do you tell if a ceiling fan is going clockwise or counterclockwise?
A ceiling fan running clockwise when looked at from above will be running anti-clockwise when looked at from below. This makes many people wonder; what direction is my fan running. This is clearly a problem of overthinking!
Ceiling fans are not meant to be looked down from above. They stay above you, so one should judge their rotation only from below.
You can tell if a fan is going clockwise or counterclockwise by looking at it from below. Switch on the fan and see in what direction its blades are turning. If they are turning clockwise, then the fan is running clockwise, and vice versa.
If the fan is already running too fast to see its blades and you are too lazy to stop and restart it, here is a lazy solution. If you are not feeling much breeze from the fan (assuming you are sitting below it), it is running clockwise. If the fan were running anti-clockwise, it would have created a strong breeze at such high speeds.
How to change a ceiling fan’s direction?
Most ceiling fans with reverse rotation come with a switch on their motor housing which you can flip to change its direction.
- Switch off the fan and wait till it comes to a stop
- Use a chair or a ladder and climb up to the fan
- Locate the switch and flip it
- Get down from the chair or the ladder, and put it back to wherever it was.
- Switch on the fan and look in awe when it starts to run in the other direction.
The remote controls of some ceiling fan models have a reverse switch for this. So, if you are too lazy, buy one of those fans. Here is such a fan if you are too lazy to find it yourself.