CO2 Demand Controlled Ventilation using On-Off Control for Energy Savings

A.E.H. Hajiah (Kuwait)


Building energy, modelling, simulation, Indoor air


An on-off type of control has been modeled using a FORTRAN program that solves the mass balance equation for CO2 buildup in each floor of a typical ten story office building. The approach is based on monitoring CO2 concentration in the building and admitting sufficient outside air by opening and closing the dampers to ensure that the air quality is maintained within specified limits. To investigate this, two hourly occupancy profiles used in the FORTRAN program were modeled in DOE-2.1 simulation program using variable air volume and constant air volume systems. Simulation was performed for a base case using ASHRAE’s recommended minimum ventilation rate of 20 cfm/person. For DCV case, DOE-2.1 simulation was performed using the minimum ventilation rates based on the CO2 concentration resulted from the FORTRAN program. Results show small savings in energy consumption for DCV case.

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