Ambient heat source availability for low-ex heating of multi-family buildings

Heat pumps (HP) for space heating and domestic hot water are well-established and considered to be a decisive technology for carbon emission reduction. However, in existing multi-family homes (MFH) their market share is still very low. In this work, the sufficient availability of the heat sources ambient air, ground probe and ground collector is assessed for one common MFH type in three different urban contexts. The heat demand of a reference building is calculated for the refurbishment state EnEV 2016 and for more ambitious refurbishment. The building is placed in the urban space types row house, perimeter block and city development. For each, the average open space around the building is estimated. Two bivalent air-source and ground-source HP system variants with gas backup boiler are designed. The necessary ambient heat extraction rates are simulated and the necessary size/distance of the heat source is calculated by using the design methods of TA Lärm, VDI 4640, Geo Hand and SIA 384/6. Finally, the resulting source demands are compared to the available space. The results show that typical row house developments have sufficient open space for either bivalent air-source or ground probe HP systems; it is also the only investigated urban space type suitable for ground collectors. In perimeter blocks, air-source HPs and ground probes are usually possible. The open space in city developments is often too small for the investigated HP system types. Here, air-source HPs may be possible if additional acoustic enclosures are installed. For HPs in city developments, combinations with photovoltaic-thermal or solar thermal collectors, multi-source systems, or cold district heat networks should be further investigated.