Optimizing Energy Renovation Roadmap for Multifamily Homes with Heat Pumps

This paper proposes a new approach to computationally optimized renovation roadmaps. The purpose of this roadmap is to determine when and how to determine which component of the building envelope and refurbish the heating system to achieve the lowest net present value. The ensemble optimization method combines the particle swarm optimization algorithm with the dynamic building simulation of the building, the envelope and the heating system. Thanks to the free choice of implementation time and renovation depth, the optimization method achieves the lowest net present value and high CO2 emission reductions, and thus makes an important contribution to the climate-neutral building stock.

An example of this method is applied to a multi-family dwelling built in 1970. According to the refurbishment roadmap, it is possible to save 6-16% in costs and 6-59% in CO2 reductions compared to the standard. The sensitivity of the refurbishment roadmap measures was analyzed on the basis of the parametric analysis. Robust optimization results were obtained with an average renovation level of about 50 kWh/m²/a for the building envelope. The preferred heating system for this is the bivalent brine heat pump system, which accounts for 70% of the heat load and is covered by an electric heat pump.