HP systems in buildings: integrating detailed heat pump models with simplified building thermal network characterization for efficient and flexible evaluations
Accurate thermal load calculation is essential for assessing building energy performance and designing HVAC systems. While detailed dynamic simulation tools — such as EnergyPlus or TRNSYS — offer high accuracy, they demand significant effort in model development and require a large amount of input data. This complexity motivates the development of simpler but reliable modeling approaches. In this work, a simplified thermal model based on the thermal network approach is adopted to estimate the thermal demand in buildings, validated against a detailed TRNSYS simulation with a deviation of 4.8% in heating demand prediction. The main contribution of this study lies in the comparative analysis of three heat pump modeling strategies when coupled with the building model: (i) a basic representation assuming constant COP, (ii) a simplified polynomial model relating COP to source and sink temperatures, and (iii) a detailed model developed using specialized simulation software, which maps capacity and energy consumption across the entire operating range of the unit. This comparison highlights the impact of heat pump model complexity on integrated system performance evaluation. The proposed approach combines a simplified and input-efficient building model with multiple levels of heat pump representation, offering a fast, flexible, and accurate calculation platform. It enables rapid analysis of coupled building-HVAC behavior, facilitating the evaluation of advanced control strategies and assessing heat pump flexibility under diverse operating conditions with reduced input requirements.