Measuring Building Occupancy
Who is in your building? How long are they there? Obtaining this information has its benefits.
- Demand controlled ventilation. Under ASHRAE 62, ventilation levels for the ventilation portion for occupants (the People Outdoor Air Rate or Rp) can be adjusted based on occupancy. The general way to do this is to measure and control based on CO2 levels. While this works well, CO2 sensing is expensive to install and properly maintain. Good data on occupancy can be used as an alternative to utilizing CO2. When areas are not at all occupied, then the ventilation requirement for the area outdoor air rate (Ra) can also be moved to zero.
- Occupancy control. Being able to see when an area is occupied could be a valuable tool for turning off lights as well as HVAC.
- Building utilization. Good data about occupancy can be a valuable tool to show how a building is actually utilized. Imagine being able to see how many people are in an office area and when or how classrooms are actually used. This information may help owners make decisions about space planning and better utilization.
- Security. Accurate people counts can be invaluable for security. It can also help with emergency evacuation and safety.