Abstract
In recent years, the adoption of energy-saving measures such as turning off the lights automatically while workers are absent and introducing office automation equipment with sleep mode have been widely promoted in workplaces. These measures tend to cause internal thermal load or absence of workers differences in workplaces depending on the presence. Therefore, an air-conditioning system design capable of maintaining an appropriate energy-saving indoor thermal environment is required. In this study, a workplace was modeled where several combinations of patterns in accordance with the absence or presence of workers were used to assume the variations in internal thermal load generation to quantitatively study different thermal load environments. Furthermore, a case study for air conditioning improvements regarding internal thermal load difference is presented for a general-type single-duct VAV system, and the effect of the improvements considering both energy saving and the appropriate indoor thermal environment. Practical design methods were also evaluated through the simulations. From the result, we found that it was important to perform dehumidification in cases where the internal thermal load was small, to stop air supply where the workers were absent and to design each air conditioning equipment satisfying the appropriate capacity according to the space scaling.
