In this type of system it is often advantageous to use a closed-loop heating/cooling system.  The temperature ranges you suggest indicate that a water or water/glycol system could work very effectively.  The system requires a circulating loop and temperature controls as well as two heat exchangers for heating/cooling the closed loop system.  Since steam is not available, there are electrical resistance heaters that could be used and either chilled water or a refrigeration system could be used to provide the cooling.  Heat load is calculated based on the desired heating/cooling times, which are transient calculations that will have a peak at the beginning of each cycle.  The system would need to be designed for that peak duty.