Heat losses in collective heat distribution systems: comparing simplified calculation methods with dynamic simulations

Heat losses in collective heat distribution systems can be reduced significantly in well-insulated and well-controlled low-temperature networks. However, this reduction is not always rewarded for in legislative energy performance of building standards in Europe. In this paper, simplified heat loss calculation methods (SCM) are compared to dynamic simulations for networks that distribute heat for both space heating and domestic hot water to low-energy houses. Results show that SCMs overestimate the distribution heat losses in these systems and that the variation in heat losses due to seasonal behaviour and control strategies is little addressed. An investigation of the influential parameters showed that they can be significantly improved by a more accurate estimation of the working time of the system and average temperature of the heat conducting medium.