| While any suitable liquid can be used, water is the easiest liquid to use in thermosiphon systems. |
| A good thermosiphon has very little hydraulic resistance so that liquid can flow easily under the relatively low pressure produced by natural convection. |
| Cooling is achieved by a patented, non-cycling free-piston Stirling engine coupled to an isothermal thermosiphon which operates without moving parts. |
| During step 2, the thermosiphon starts to operate and defrosts the air evaporator. |
| If the piping of a thermosiphon resists flow, or excessive heat is applied, the liquid may boil. |
| This article presents a heat pump for simultaneous heating and cooling in which a thermosiphon forms to defrost the air evaporator. |
