Implications of Variable Air Volume Flow and Occupancy Diversity on Office Building Energy Efficiency
In Kuwait, nearly seventy percent of overall building energy utilization is associated with air conditioning (AC) sector, especially in the residential sector. In a building envelope, there is heat transfer, in addition to; there are multiple zones in an office building, which requires distinctive heat balancing that consequently, influences the AC systems and subsystems. The manner in which the occupants occupy the various zones of the building is diverse, resulting in unusual load demand for AC and hence associated inadequacies. To evaluate the implications of variable air volume (VAV) flow in AC and occupancy diversity for an office building, the operational data for carbon dioxide sensors were analyzed and studied. The carbon dioxide concentration is one of the important indicators for analyzing the building occupancy. By knowing the occupancy in a building, not only the indoor air quality can be maintained, but also, the energy efficiency objectives corresponding to the HVAC operations can be maintained.
The correlation between the CO2 concentration and corresponding occupancy in an office building is analyzed experimentally in this study, by maintaining real operating conditions throughout the year. Graphical trends of the CO2 concentration and its relationship with indoor temperature were plotted which provided information about the important parameters affecting occupancy diversity in the selected office building. The important elements used for estimating the occupancy diversity was also discussed in the paper. Therefore, the quantification of HVAC system energy efficiency influenced by occupancy diversity can be distinguished. Even though the proposed framework is for a selected office building, this can be applied to other types of building geometries and layouts by instituting appropriate adjustments.
Dr. Sreekanth K. J. is a research scientist of the Energy Efficiency Technologies (EET) Program at the Energy and Building Research Center (EBRC) at Kuwait Institute for Scientific Research (KISR). He joined KISR in January 2015 after obtaining his Ph.D. from the National Institute of Technology, India, in 2013. He has more than 50 international journal & conference publications. He completed projects on the energy efficiency strategy development in the transportation sector and energy storage technologies optimization studies, besides working on the Kuwait energy outlook project. Presently he is serving as the newsletter editor for the environmental systems division (ESD) of ASME.