How it works

Nonetheless, this equipment would function, if only with a very unfavorable efficiency. In the upper half, coolant would be conducted, under pressure, through a heat exchanger before the engine radiator. Heat would be extracted from the coolant. The pressure would be built up by the (powered by the engine) pump on the left, and by the check-valve on the right. At the bottom the coolant would flow through a heat exchanger in the heating shaft. Due to the fact that it would be sucked into this half of the piping by the pump, it could absorb heat.

To increase the efficiency, one would have to experiment with the circulating liquid. Should one use oil instead of water, a better corrosion prevention is achieved, however, the transmission of heat is halved. Ideally suited is a liquid which has a lower boiling point than water.

To convert 100°C water from its liquid form completely into steam, 5.4 times more heat is necessary than to heat the same quantity of water from 0 to 100°C. If a liquid, on the way from the radiator to the interior evaporates and on the way back becomes liquid again, it could carry substantially more heat. One could get by with lower pipe cross sections (low volume) and only a little liquid (low weight). This is exactly the behaviour of the coolant in our modern air-conditioning units. 09/09