Peltier+Heating+and+Cooling

Our students have done considerable research with Thermoelectric Cooling (TECs), such as this senior project.

Also, Robert Van Buskirk from Kuyere! has done some work using TECs for heating, achieving better than 100% heating efficiency (images provided below - Temperature reading is in Fahrenheit). Robert says:

"Here is what happens when you use Tec's as pot heaters. I put four sets of three on series, and ran them at 5.5V each. They maintained a 50 to 60 degree F difference between top and bottom (i.e outside and pot).

I think this means, you get a little heat pumping, when the water temperature in the pot is less than 55 degrees higher than ambient. For Africa this should give you a water heater that can be greater than 100% efficiency when the water temperature is less than 135 deg. F (80 + 55). How much greater than 100% depends on the efficiency of heat transfer in to the cold side of the thermoelectric chip. The TEC chips can be purchased for less than $3 each. I think the academic journals would enjoy a paper on a $50, >100% efficient solar electric hot water pot for decreasing wood burning in rural Africa. Even, if it is only %110 efficient, the >100% bit should have a little wow factor to it."

If you look closely, you'll notice that Robert has three TECs stacked up in each pile. He writes: " Note, 30 minute pasteurization temperature is 145 degrees F. I am going to try a fourth in series TEC. Then the pot may be able to maintain >100% efficiency up to pasteurization temperature." Please see this about some ideas of TEC cooking/cooling.