Energy Consequences of Non-optimal Heat Pump Parameterization
Résumé
The substitution of low-performance gas and fuel boilers by air to water electrical heat pumps is a solution to meet the energy challenge to reduce GHG dwellings emissions. Indeed, most dwelling emissions in Europe are due to heating and DHW generation with fossil fuels. Apart from low carbon emissions, high energy savings are expected from rated performances, but an AWHP may not deliver the expected efficiency because of a bad commissioning. Nowadays, these machines present a high number of parameters – over 40 on average – to be set during the installation, which makes this process very complex. Unfortunately, the parameter setting is a crucial step for the proper operation of the system throughout its life cycle. A non-optimal choice of AWHP parameters may lead to severe performance losses or discomfort. The first part of the paper describes the functions and parameters that the installer must adjust for the commissioning phase. In a second step, the consequences of a non-optimal parameterization of an AWHP are evaluated. This analysis is based on a computer model using Modelica language. The model consists of a heating system, installed in a typical detached dwelling. Simulations are run by pairing the heat pump with the dwelling and the heating system. Simulations show the potential energy savings and the accuracy of indoor air control when control parameters, in particular the heating curve, are adapted to the dwelling and to the heating network. Final results confirm that an optimization of the parameterization of an AWHP makes a significant difference, in both energy savings and indoor air temperature control accuracy.