Solar and pellet combisystem for apartment buildings: Heat losses and efficiency improvements of the pellet boiler

This paper is based on the analysis of the solar combisystem installed in a 4-storey apartment building in Sigulda, Latvia. The combisystem consists of: 42 m² of flat plate solar collectors, a 2.35 m³ accumulation tank and a 100 kW pellet boiler as the auxiliary heater. This paper focuses on the optimisation of the thermal performance of the pellet boiler.