Turning on your ceiling fan in winter to help keep your room nice and snug initially may not seem logical, given that a fan usually cools you down. Your ceiling fan, however, sports a handy winter mode that may well be a feature rarely used, purely because we don’t know what it does.
Ceiling fans only work in winter when they are rotating in the correct direction and if certain other factors are present.
Ceiling fans must rotate clockwise in winter. In this rotation, the lower points of the pitched blades lead, and air moves upward. This draws cold air up, displacing warm air gathered at the ceiling, and the warm air moves into the occupied space. Winter mode is only effective if used with a heat source.
Should a Ceiling Fan Be Blowing Up or Down in Winter?
You want the air to blow upward in winter.
During the colder winter months, set your ceiling fan to winter mode by toggling the reverse switch. In this mode, the ceiling fan will turn in a clockwise direction. When it spins clockwise, the lowest point of the pitched blades leads the rotation and this causes air to be pulled up.
The air that is drawn from below the fan is pushed into the space above it, displacing the air that is there, which then moves out from the fan and down into the occupied space of the room.
Why Do Updrafts Work in Winter?
Hot Air Accumulates Near the Ceiling
Warm air is less dense than colder air, so it naturally rises. In a room, the ceiling prevents the warmer air from escaping, so it forms a layer against the ceiling until it is either replaced by even hotter air or the air cools and sinks lower.
The coldest air is found at floor level as gravity has a greater effect on the denser cold air. The cold air layer is why your feet may feel cold while the rest of your body feels comfortable.
As you can imagine, this natural distribution of hot and cold air is good in summer but far from ideal in winter when you want the warm air over your body and you don’t want cold feet!
Ceiling fans rotating clockwise are supposed to counteract this natural air distribution.
Ceiling Fans in Winter Mode Redistribute Air
As already stated, when the ceiling fans rotate clockwise, the blades cause an updraft.
The air that is pulled from the occupied space of the room beneath the fan is going to be colder air that you don’t want enveloping you.
The air that is displaced at the ceiling by this cold air and moved into the occupied areas of the room is going to be the warmer air that has gathered at the ceiling.
This is a much more beneficial distribution of air.
In addition, the updraft created by a ceiling fan is not as strong or as concentrated as its downdraft. So, even on higher speed settings you should barely feel the air moving past you. This prevents the creation of the wind chill effect, which would negate the whole purpose of running the fan in winter—making you warmer!
There are limitations to how much warmer a ceiling fan can make you, even when spinning clockwise in winter mode. This is because it cannot add thermal energy to a room—it cannot raise the ambient temperature. All it can do is help to more effectively distribute the heat that is already in the room.
In reality, instead of feeling a blanket of warm air flowing over you, the air is simply circulated throughout the room. The various layers of air are combined, forming a uniform air temperature throughout the room that is not overall higher than before you turned the fan on.
The most it can do is create a slightly more comfortable ambient temperature in the space that you occupy.
Overcoming the Limitations
You might be thinking that there is no point to running a ceiling fan in winter mode if it is not going to have any significant affect on how warm you feel in a room. Well, with the simple addition of an external heat source, your clockwise-rotating ceiling fan turns into a wonder device!
Adding heat into the room by means of a radiator, space heater, fireplace, gas heater, etc., means that you are increasing the ambient temperature. But you are not stopping the natural inclination of hot air to rise and sit at the ceiling.
The overall temperature of the room will rise, but most of the heat will still be sitting at the ceiling, where it is no good to anyone.
By running your ceiling fan in winter mode, you ensure that the heated air is pushed back down into the occupied space of the room, where it can keep you warm.
You can even make the system even more effective on those dry winter days. By running a humidifier, you add moisture and heat to the air. The ceiling fan in winter mode helps to distribute it both of these elements throughout the room.
Energy-Efficiency of Combined Approach
The designs of the heat sources mentioned in the previous section are such that you will end up with cold spots in the room.
These heat sources are typically located to one side of the room. The areas in front of the heat source will be nice and toasty, but the hot air rises before it can reach the occupied areas of the room further away from the heat source.
In these situations, a ceiling fan set to winter mode will make a significant difference because it evens out heat distribution.
Furthermore, when you don’t have to keep cranking up the thermostat to warm the areas more distant from the heater or fireplace, you save energy and money on heating.
You can start taking advantage of the ceiling fan’s winter mode as soon as the fall temperatures start dropping.