Comparison of Energy Harvesting Concepts for Heating, Ventilation and Air Conditioning Systems

Heating, ventilation, and air conditioning systems contribute significantly to the overall energy consumption of buildings. In order to operate these systems more efficiently, the airflow distribution must be known for the entire facility. This information can be obtained by installing wirelessly connected sensor nodes. Power supply for such distributed data acquisition systems is a challenge because it is difficult and costly to install cables. Therefore, in this paper, energy harvesting strategies are investigated to supply these sensor nodes with energy, with the objective of reducing installation and maintenance effort. The main challenges are the relatively high energy of 2 Ws needed per measurement and the fast measurement interval of one minute. The investigated energy forms are airflow, thermal and solar energy. The aim of this study is to determine which energy forms are suitable under typical operating conditions in HV AC systems and how they can be used. As the same measurement procedure is used for each energy form, an objective comparison can be drawn. It is concluded that solar as well as airflow energy are promising to harvest from, while thermal energy is less suitable in most cases.