A control method for increasing the heat usage efficiency of nearly-zero-energy buildings with heat pumps
¹Estonian University of Life Sciences, Institute of Technology, Chair of Energy Application Engineering, Kreutzwaldi 56, EE51006 Tartu, Estonia
²Aalto University, Department of Electrical Engineering and Automation, Maarintie 8, Espoo, Finland
*Correspondence: heino.pihlap@emu.ee
Abstract:
In the retrofitting of older buildings with central heating into nearly zero-energy buildings more and more air to water heat pumps are used. These heat pumps are normally connected to heating systems, producing heat only on demand. The greatest demand for heat occurs when the outside temperature and therefore the COP of the pump is lowest. Outside temperature varies during the day, meaning it is possible to save energy by producing and storing heat in a situation where the COP is higher. To determine the periods with higher COP values weather forecast data and COP curves are used. The data enables to rank and select time periods for heat production. This in conjunction with the heat demand curve of the building enables to create an operation schedule for the heat pump. The aim of the study is to develop heat pump control methods for renovated buildings to comply with nearly zero energy building codes. Dependent on the heat pump and weather conditions, up to 10 % of the electricity demand for heating can be decreased.
Key words:
heat demand modelling, heat production scheduling, heating season, optimization, temperature fluctuations