"Richard J Kinch" wrote in message
.. .
Do the model engineering fanatics ever build heat pumps? All I can recall
seeing are various engines.

I was trying to think up a project that would not look too eccentric and
would entertain people. It occurs to me that you could build a little
hand-cranked heat pump that would chill a beverage can from room temp down
to near freezing. Since that represents only about 50 BTUs it shouldn't
take that much muscle in a properly engineered device. It would all be
belt-driven from a hand crank, running something like a Procon pump to
compress a refrigerant, with a belt-driven fan over a condenser, and an
evaporator that was a saddle to hold a can sideways that was slowly spun.
The saddle could contain a water bath to make an ice bank to chill the can
without freezing it.

Or maybe just a simpler version to blow some cold air in your face when
you
crank it.

Or what would be even more impressive would be a gadget that made cold
beer
on one end and hot tea on the other.

Stirling heat pump. They work great, and have fewer lubrication problems
than Stirling engines. And no stainless or superalloys. You can make them
out of aluminum screw-machine stock. One end is hot, the other end is cold.

I've had thoughts of making a Stirling cooler myself.

--
Ed Huntress