Abstract: The option of reversible heliothermal system on the basis of the Multipurpose Solar Panels (MSPs) for effective round-the-clock maintenance of favorable temperature condition in rooms at sharp differences of day and night ambient temperatures is presented in the study. In hot time of day of MSPs carry out function of the cooling protective surfaces due to transition of the liquid heat carrier to a vaporous state. With fall of temperature through MSP the heat carrier heated in hot time of day is pumped over, selecting energy from the thermal accumulator. Energy in the thermal accumulator collects upon transition of the heat carrier from vaporous in a liquid state after run via the compressor.