Four corn. paraffins, NaNO2, NaNO3 and KNO3 salts and their corm mixt. (contents 53%, 40% and 7%, resp.) were studied for thermal energy storage capacity by thermal anal. Enthalpy, temp. of phase change, thermal stability and reactivity were detd. Applicability of the phase-changing materials was studied in heat accumulators made of Cu, Al or stainless steel tubes in a lab. stand during charging and discharging.