"trader_4" wrote in message
...
Not really, because again most of the energy from the motor is
not resulting in heat. I made that mistake myself, suggesting that
you could measure the wattage using a Kill-a-Watt. You can measure it,
but you can't then say because it's pulling 50W that it's generating
50W of heat in the room.

I understand your thinking, but all the power a fan is using in a closed up
room is going to generating heat.

Part of the power to turn the motor is being used in the wiring, part is
lost in the bearings of the motor, and whatever is left over is moving the
air. When the air is moving, that movement is being converted back to heat.

If it was being used to blow air out of the room, then much of the enegry
used to move the air would be dissapated as heat outside the room.

Just plucking out numbers from the air, say the fan draws 100 watts from the
AC line. All 100 watts will be heating the room unless you blow air out of
the room. The fan may only use 25 watts to heat up the motor due to
electrical and mechanical losses. The other 75 watts will be converted to
heat when the air molicules rub against each other and slow down. Just like
rubbing your hands together.

Same as a light bulb. So much goes to generating the light, and whatever
the light hits heats up. So unless there is a window that lets a few photons
out, all the power of a light bulb of any kind will go to heating up the
room. Some types of bulbs are just more efficiant in making light than
others so you can get an equivilent ammount of light with less wattage and
het.