Paper No 543 – Hydronic Optimization for a good Heat Pump Performance – 14th IEA Heat Pump Conference, Chicago, USA
Many gas-fired boilers are likely going to be replaced with heat pumps in the very close future [1], supported by current energy plans. Air-to-water heat pumps will be increasingly used as sources for hydronic heating systems. Consequently, water-based systems need to have low OPEX for obtaining a solid business case with good ROI. As a common pragmatic solution an A/W heat pump is recommended with low temp. heating systems, typically floor heating, where the temperature curve is lower compared to conventional radiator heating system. However, in most boiler replacement cases radiators are installed in residential and residential like buildings. Acceptable ROI is obtained by having superior SCOP of the HP together with an optimized design of the hydronic system, including distribution and heat emission. This paper describes the role of hydronic controls, which in traditional radiator heating systems is governed by TRVs and Hydronic Balancing, the relation to the HP efficiency, with the goal to achieve best ROI. This is realized without compromising comfort, and is a marginal cost of the additional Building Automation and Control devices to be installed or upgraded together with the HP. Investigations and results are oriented to parameters which leads to reduced operational temperatures and longer lifetime for the HP.