Virtual Outdoor Airflow Meter for the Ongoing Commissioning of HVAC Systems: Lessons from a Case Study Building (OR-16-C067)

The use of trend data from Building Energy Management Systems (BEMS) is a cost-effective solution to provide the necessary data for the ongoing commissioning. This paper presents the use of trend data, recorded every 15 minutes, with a virtual air flow meter for the estimation of the outdoor air flow rate brought in the air-handling units. A virtual flow meter estimates the value of a physical variable in the heating, ventilating and air-conditioning system where a physical sensor does not exist. For this purpose, a mathematical model is used along with measurements from available sensors in the system. In this study, a virtual air flow meter was developed to estimate the outdoor air intake, and the results were presented as the ratio α of the outdoor air flow rate to the supply air flow rate.