Simulation and experimentally assisted development of a mini-split facade-integrated heat pump for minimally invasive renovations

Co-Betreuer: Fabian Ochs, Rainer Pfluger

Kurzfassung

Research gap identification and objectives

One of the major challenges in multiple-family buildings (MFB) subjected to deep energy renovation is the substitution or update of the system supplying space heating (SH) and domestic hot water (DHW). Decentral heat pumps can be crucial in this context but the source accessibility, especially in urban environments, is heavily constrained. On one hand, facade-integrated heat pumps allow for low invasiveness, compactness, modularity and high degree of prefabrication. On the other hand, a comprehensive design procedure from the component level up to the building level is needed to guarantee efficiency. A mini-split facade-integrated air-to-water heat pump for minimally invasive renovation is being developed and optimized at the Unit for Energy Efficient Building by means of coupled fluid-dynamics (CFD) and refrigerant cycle simulations. CFD-assisted design allows for minimization of the pressure drop in the outdoor unit, homogeneous flow and low sound emissions. A prototype of mini-split heat pump will be built and simulation results will be validated through extensive measurement campaigns. Laboratory measurements will also test the functionality of the prototype under varying boundary conditions and will indicate the direction for possible further improvements.