Automated Heating Valve (AHC)

Prototype of an autarkic thermostatic head for home automation

If room heating is a function of time or dependent on the presence of people then an intelligent control can contribute to substantial energy savings. Current market solutions, i.e. electronic thermostatic heads, work with batteries.

Our contribution was to develop a prototype of a fully self-sufficient heating valve using a thermoelectric generator (TEG) and an optimized booster for energy harvesting. At a temperature difference of 6 °C on the TEG, the valve can be completely opened or closed three times within an hour.

A special characteristic is the possibility to operate thermal energy harvesting at temperature differences of less than 5 K. In order to achieve this we developed a highly efficient booster for low input voltages of less than 20 mV and an output voltage of 3.6 V achieving 32% efficiency. With an input voltage of 120 mV input voltage we could achieve an efficiency of 74% (@ output voltage of 3.6V) on the prototype t 3.6 V output voltage. The high energy yield allows the use of small and inexpensive TEG leading to substantial reduction of system costs.