The problem of heat storage in low- or ultra-low-energy houses is becoming a crucial issue. The general purpose of this study was to determine the potential for utilising heat gain recovery in a building. The proposed solution is based on an auxiliary latent heat storage tank using paraffin RT24. The tank is connected to an integrated heat recovery system that supplies heat from the internal loop of a mechanical ventilation system. The storage capacity of the tank was determined using the proposed parameter “excess of heat gains” of the thermal zone, and was obtained by measurement. The detailed construction of the tank, the phase change material properties and the quantity were proposed. The data that was collected allowed for the calculation of the temporary charging level as well as the overall seasonal energy stored in the tank. It was shown that during the heating season, the temperature could rise above the set-up value of 20 °C by as much as 8 K at maximum. Although the analysed building was characterised by heavy construction and high thermal mass, the additional heat could be effectively stored and utilised to cover the energy demand of the zone at the level of 88 MJ/a and 208 MJ/a, depending on the airflow rate between the rooms and the heat exchanger, for 140 and 420 m3/h, respectively. The expected energy effect for a low thermal mass construction, e.g., a timber frame was much higher and the results obtained by using the numerical simulation were 116 MJ/a for 140 m3/h, and 273 MJ/a for 420 m3/h, respectively.
Inter-seasonal Heat Storage in Low Energy House: From Requirements to TESS Specifications
