Paper No 652 – Simulation-assisted development of a mini-split air-to-water façade-integrated heat pump for minimal invasive renovations – 14th IEA Heat Pump Conference, Chicago, USA
One of the challenges in renovated multi-apartment buildings is the upgrade or substitution of existing systems delivering space heating (SH), domestic hot water preparation (DHW) and cooling (SC). Construction and installation works are complex and their related costs are high. The European heat pump market currently lacks compact and cost-effective solutions for minimally invasive, so-called serial renovations, which at the same time exhibit high efficiency, an aesthetically pleasing design and low sound emissions. Façade-integrated decentralised small-scale heat pumps (HP) are regarded as a promising solution to increase the general acceptance for flat-wise heating solutions. Because of the compact design, they require a deeper investigation of the fluid-dynamics within the outdoor unit (evaporator) to guarantee an adequate efficiency of the final product. Based on these considerations, a mini-split air-to-water façade-integrated HP for DHW was developed. The design of the outdoor unit was optimised by means of computational fluid-dynamics simulations (CFD) and the overall efficiency evaluated through refrigerant cycle and system simulations. To conclude, the prototype was tested dynamically in a double-room climate chamber with controlled indoor and outdoor temperature conditions.