Energy consumption was quantified in the drying of 2.5 cm thick red oak lumber ina 1.2 m3steam heated experimental dry kiln. The aluminum pre-fab kiln is located indoors and was wrapped with 5 cm thick extruded polystyrene (R=10) for the experimental drying. Transmission loss accounted for about 80% of the energy/kilogram of water removed from the wood. The maximum value was for the 60°C DBT due to comparatively high transmission loss combined with maximum venting loss. Batch venting reduced average energy consumption per kiln run by over 6% compared to the conventional kiln schedule.