@ARTICLE{Olczak_Piotr_The_2020,
 author={Olczak, Piotr},
 volume={vol. 23},
 number={No 2},
 journal={Polityka Energetyczna - Energy Policy Journal},
 pages={91-104},
 howpublished={online},
 year={2020},
 publisher={Instytut Gospodarki Surowcami Mineralnymi i Energią PAN},
 abstract={The analysis of a solar installation operation was conducted on the example of a detached house in the Lesser Poland province in Poland. A gas boiler and three flat-plate collectors are located inside the house, which are used for heating water in the hot water tank with a volume of 220 dm3. The installation was established in 2012. The heat measured system (for solar gains) was added in 2014. In 2015–2019 solar heat gains measured per area of absorber were higher than 340 kWh/m2. During a two-week period in June 2015, the insolation on the horizontal plane and the temperature were measured in 4 different points of the hot water tank. On this basis, heat losses from the storage tank were determined, i.e. a decrease in temperature during periods with and without the consumption of hot water by the residents. During this period, a temperature higher than 80°C was observed several times in the hot water tank. In two parts of the hot water tank, rhe determined temperature decreases were used to obtain the heat loss amount. In the analyzed period (2 weeks), 9 days were observed with solar heat gains higher than 9 kWh/day. For these days, the value of heat loss from the solar hot water tank was estimated at over 6 kWh/day. This data corresponds to the actual heat demand for hot water preparation in the building at 7.3 kWh/day. The correlation between daily solar heat gains and solar hot water tank heat losses were also determined. In addition, based on the amount of heat losses, the value of the tank loss coefficient was estimated. The obtained value was compared with the manufacturer’s data and reference data.},
 type={Article},
 title={The influence of excessive solar heat gains on heat loss in the hot water tank – case study},
 URL={http://ochroma.man.poznan.pl/Content/117207/PDF/06-PE-Olczak.pdf},
 keywords={renewable energy, solar energy, flat plate collector, hot water tank, tank loss coefficient},
}