The paper presents results of the analysis related to determination of the value of the coefficient of heat permission through the cover of a facility and thermal issues (temperature, heat amount) at discharging a stone accumulator. For calculation of this coefficient, relation including inside temperature change as a function of variable amount of heat transferred to the cover by radiation and heat transferred outside the facility by permission was used. Basing on the value of the calculated coefficient of heat permission the value of temperature inside the plastic tunnel in the process of supplying heat from a stone accumulator was determined. At the accepted decision values (temperature of surrounding is 8ºC, initial temperature in the tunnel at the level of 15ºC and the stream of pumped air amounting to 500 m3·h-1) and at the accepted cycle of dis-charge (9 hours), the scope of temperature changes inside (in comparison to the initial value) was within -0.2 to 2.4 K. Moreover, simulation calculations of the impact of the heat supplied from the accumulator, where initial temperature of the accumulator and stream of pumped air were included as variables, on the final values of the soil accumulator temperature, were carried out. Furthermore, quantity relations between final temperature of the accumulator and its room temperature and the stream of pumped air were determined. Non-linear estimation with the use of quasi-Newton method was applied for determination of this relation.