A reversible reaction process can be used in a chemical heat pump for cooling or heating purposes, depending on the thermodynamic conditions in the reactor. In this work an experimental chemical heat pump with a reversible reaction of calcium oxide and water is discussed. The intention of the research work was to intensify heat and mass transfer in the reactor bed during the hydration phase at low operating pressure, which would enable the use of the reaction device as a part of high-efficient cascading sorption cooling device. Due to a low thermal conductivity of the reactive salts, the expanded graphite is used as a binding material in the reactor bed. To intensify mass transport to reaction sites and to shorten the hydration reaction the reactor bed is prepared with additional vapour channels. From measurement results the expected heat and mass transfer intensification, which would be enough for a thermally efficient heat pump, is observed. It is also concluded that an exact dimensioning and a proper preparation of the matrix are crucial for reaching the required cooling or heating performance.