The features of nonstationary heat transfer of one layer of balls of the same size were studied in a fixed layer of liquid. The experiments were carried out in a cylindrical thermostat with a diameter of 128.9 mm filled with glass balls of 8.9 and 16.0 mm diam and polyoxymethylene balls of 9.0 mm diam with the highest possible packing density. The ball packing was filled with distilled water to a level of 0.1-0.2 mm higher than the ball diameter. The temperature of the ball packing surface was measured using a NEC 7100 thermal imager with a step change in temperature at the outer boundary of the packing. It is shown that, for a monolayer of balls of the same size in a stationary liquid, the temperature field is symmetrical relative to the packing center and the value of the effective thermal conductivity coefficient is constant over the packing cross section, both during heating and cooling. It has been found that the heat transfer coefficient and the time for establishing thermal equilibrium of a ball packing in a layer of stationary liquid at the same temperature difference depend on the heat flux direction at the packing boundary. The numerical values of the characteristic time of thermal equilibrium establishment in the heating and cooling regimes differ from each other by several times; whereas in the water layer without balls, this difference does not exceed 30%.