How much heat does a 100 watt fan make?

Status
Not open for further replies.

DougoMan

Senior member
May 23, 2009
813
0
71
Sorry for my ignorance of physics, but anyway:

If I had a fan in a room that used 100 watts, would the room get warmer at the same rate as if I had a 100 watt electric heater in the room?

I think it would, but need a well articulated explanation of why.
 

Bignate603

Lifer
Sep 5, 2000
13,897
1
0
100 watts is 100 watts. For electronics, as long as there's not some way for it to dissipate heat out of the room, every watt that goes in to the device will be dumped into the room as heat.
 

DougoMan

Senior member
May 23, 2009
813
0
71
Well say you had a 100 watt lightbulb. Isn't some tiny amount of the energy that goes into it converted into light?
 

Bignate603

Lifer
Sep 5, 2000
13,897
1
0
Well say you had a 100 watt lightbulb. Isn't some tiny amount of the energy that goes into it converted into light?

Yes, but when that light hits objects in the room and is absorbed it is turned into heat. In a closed system (meaning no energy can escape) it will all turn to heat eventually.
 

edro

Lifer
Apr 5, 2002
24,326
68
91
If the house is perfectly insulated, yes, it will increase the air volume energy by 100W, exactly as a heater would.
Fans would actually heat the room up quicker than a heater, because they force cooler air to move across the motor (heater).
Heaters rely on convection and tiny amounts of conduction and radiation.
Fans cause forced convection and tiny amounts of conduction and radiation.

Fans feel cool because they increase air movement across your skin.
As long as the air is at a lower temperature than your body temperature, you will dissipate body heat to the air and feel cool.
If you are sweaty, which everyone is to some degree, you will also feel the evaporative effect, which transfers heat energy at a much higher rate than convection alone.

100W through an entire house is not much though, so fans are still effective if you don't have AC, even with the windows closed.
 
Last edited:
Status
Not open for further replies.