EnergiBUS4home – Sustainable energy resourcing in low-energy buildings

Highlights: • Connecting domestic appliances with the heat pump and ventilating system in a low energy building. • Evaluating the energetic performance of the building for one year round. • A location in Southern Germany is selected. • The energiBUS system saves round about 200 kWh/a. • The COP results into 4.4 without improved system synchronization. Since the overall energy consumption of residential buildings has significantly increased over the recent decades many technologies have been established to reduce the power consumption of households significantly and to use energy efficiently. In general, thermal energy for heating or cooling devices of domestic appliances is generated decentralized by the respective device and not in one central location of the building. This paper introduces a novel system design, where domestic appliances like the washing machine, dishwasher, condensing dryer, refrigerator and freezer are thermally interconnected to the heating and ventilation system in a low-energy building via the "energiBUS" – not only in terms of warm water, but also for cooling tasks. The integrated system concept is presented and load profiles are analyzed to discuss the functionality of the system and the energetic flows. The system benefits from the replacement of power consuming heating and cooling devices of the domestic appliances and the synchronized operation of the heat pump due to an additional hot and a cold water storage. In comparison to a system without the "energiBUS", the overall power consumption of a four-person family home in passive house design is reduced by about 200 kWh/a without the improved heat pump synchronization.