AWESOME engine dyno information thank you! Even I can admit when I learn something new.

Now it's your turn

Defroster used in rear windows of automobiles is a heating element applied directly to the window. However, the defroster used for the front window turns on the air conditioning. A/C consistes of 4 major components of which I'm sure you are familiar with since you've probably removed 3 of them. Compressor, condensor, expansion valve and evaporator...

The front defroster actually utilizes the air conditioning to remove water vapor from the air. The result is very dry air that likes to absorb moisture. When you blow dry air against a surface that has condensed water on it (your window) the water evaporates, clearing the surface. You can blow warm air at it too, but the real key for defogging windows quickly is DRY air. You'll notice, whenever you've run the air conditioner for a while, your car will appear to be leaking water. That is the condensed water collected from the air being blown into the passenger compartment.

BTW, have you ever used an eddy current dyno? I would imagine those would be the most ideal... no head loss from water flow. I was reading about one the other day. Looked pretty sweet... It's essentially a generator that you can apply a variable resistive load to, mounted on a force transducer... voila! torque!