Window Mounted Coffee Cup Engine

[chmorgan]

Any ideas on a way to mount the coffee cup engine to a window to take
advantage of the interior and exterior temperture differences?

[info74]

You didn't say where you were located, but I'll assume you live in some part of the world where it is bitterly cold in January instead of some place like San Diego. I would suggest trying this with a MM-6 heat of your hand Stirling engine.


Make a bracket so that the engine is supported horizontally with the "bottom" against the cold window. Try to locate it in a part of your house where the window gets a nice blast of hot air from the furnace and where the window doesn't get much sun. If you've got enough temperature difference across the engine you should be able to start it and have it run until the first warm day of spring.


The MM-1 and MM-5 Coffe Cup Engines(tm) need roughly a 40 deg. F. temperature spread to run, so if the window is cold enough (and the room is well heated that should work too.


Remember to send us a picture if you get your engine running like this. Better yet, set up your own free Stirling engine web site on our server to show everyone how you did this!

[stan.hornbaker]

Build a little 'window green house' to fit the width of the window sash. If you have a multi-paned sash available and can remove one pane the 'green house' will be smaller and easier to make. Make a horizontal plywood bottom and provide a hole, just a bit smaller than the engine base for the engine to sit over. Make some blocks or use modelling clay to hold it in place and seal around the hole.
Orient the engine at 45 deg. so that it assists the flow of room air over the top of the engine.