Using Co-simulation between EnergyPlus and CONTAM to evaluate recirculation-based, demand-controlled ventilation strategies in an office building

Abstract

A coupled energy, airflow, and contaminant transport building model was developed using co-simulation between EnergyPlus and CONTAM. The model was used to analyze different strategies to control supply air delivery and return air recirculation rates including the use of demand-controlled ventilation (DCV) strategies. Strategies were evaluated for their effects on indoor pollutant concentrations and energy use of an office building in Trondheim, Norway. Typically, office buildings in Norway employ 100% outdoor air ventilation systems. Measurements in the office building served as the basis to develop the coupled model. The same building was also simulated with the outdoor conditions of Beijing.The results showed that all the simulated DCV strategies yielded reductions in energy use compared to a baseline, schedule-based strategy. Using recirculation of return air was also an energy efficient measure which increased the otherwise low indoor humidity levels in Trondheim. Using CO2-based DCV may result in increased levels of indoor particulate (PM2.5) from outdoors but using PM2.5 monitoring in the ventilation control strategies reduced indoor concentration of PM2.5 and energy usage. However, the low outdoor PM2.5 levels in Trondheim may not justify its use in this location. The Beijing case revealed that the indoor levels of PM2.5 can be reduced below the World Health Organization requirement of annual average of 10 μg/m3 using PM2.5 control.Co-simulation results revealed that it is possible to both reduce energy use and improve IAQ by controlling the outdoor air fraction based on multiple pollutants while also considering local outdoor environments.