The interest in alternative power units has increased. It is now clear that a conventional combustion engine is not a good energy transformer. We study the possibilities of using alternative heat engines - steam engine, Stirling engine, hot air - Ericsson engine. The Stirling engine has been given a lot of attention, many research projects have dealt with the use of this engine. A very important part of a hot air engines, Stirling or Ericsson engine, is just a heat exchanger, which is the basic energy converter from the fuel to the engine. ukryj opis