OT: Motor kw's lost as heat

Just a quick question for anyone who knows. I want to know, approximately, how much energy in a motor is lost as heat?

I am interested in tefc sqirrel cage motors, of between 100 - 200hp and hoping to recover some of this to save on warehouse heating costs.

Thanks, Markie

Should be able to get motor efficiency from the factory data.
So for a 100 HP motor ie about 75 Kw
IF 90% efficient then 10% lost -- about 7.5 Kw

1 Kw = 3412 BTU
So total heat loss is about 24,000 BTU
Probably wont heat the warehouse but sure will heat the office.
The trick is going to be to keep the motor and machine out of the office to prevent deafening
AND to get heat from motor to the office.
THEN what are you going to do in summer when office is stifling??

Dan Bentler

Thanks, We already use the air that cools two big screw compressors (140kW) to heat the warehouse - with a "Summer" and "Winter" fan!

The plant I work in has several mills and the whole process generates a lot of heat - which we vent outside!!

I think some ducting and a simple diverter would pay for itself in a month. Of course, I'll need to fit a touch screen, a whole heap of sensors and a plc..........

My data is based on experience not on mathematics, First thing i do is turn on the motor without any load and measure current on every phase, this current should be normally around 20-25% of full load current, if current is higher than this value i prefer to change the motor, so i ask vendor to run this test before buying a new motor. A higher value means that current is lost inside the motor as heat.