Operation assessment of hybrid heat source for heating the building and preparation of hot water in the fire brigade building

Abstract

The paper presents the annual results of monitoring a hybrid heat source consisting of a condensing gas boiler, ground and air heat pump, and solar collectors. A boiler with a nominal heat output of 186 kW works with an 81.1 kW ground-source heat pump, a 27.4 kW air-to-water heat pump and six solar collectors. The hybrid heat source is located in the fire brigade building to provide heat for space heating and ventilation and to supply domestic hot water. The annual monitoring results of the hybrid heat source were analysed in detail. The entire heat plant was equipped with measuring instruments enabling determination of heat output of individual devices, average boiler efficiency in the heating and summer season, the heating seasonal performance factor for ground and air heat pump, gas consumption by the boiler and electricity consumption by individual devices. The heat energy produced by individual devices was determined for a given period. Selected results of the economic analysis are also discussed. The annual costs of purchasing gas and electricity consumed by heat pumps were compared. Boiler efficiency as a function of parameters characteristic for a hybrid heat source was presented. The use of ground and air-source heat pumps and solar collectors reduced the consumption of natural gas during the year by 21,621 m3. As a consequence of the reduced natural gas consumption, the carbon dioxide emissions decreased during the year by 13.32 Mg.