SimplyDrain – Simplest solar drainback systems as add-on for DHW preparation in multifamily houses

A simple concept of a solar thermal drainback system is developed that can be used as add-on when refurbishing existing domestic hot water preparation in multi-family buildings. Three variants of the concept will be designed by means of energy simulation and calculation of levelized cost of heat. The most promising variant will be sized with thermohydraulic simulations and built in the lab. This demonstrator will be used to analyse and show safe operation conditions and the feasibility of the system concept.