HVAC control systems have come a long way since the first thermostats. But in spite of technological advances, many buildings are still run as they were in the 1970s. It’s time to rethink HVAC scheduling to get the best return on your investments in modern technology.
If your campus or building is typical, you schedule HVAC based on a daily or weekly schedule, returning your HVAC systems to unoccupied settings only at night, on weekends, and on holidays. You may often need to override schedules for exceptions, such as late night or weekend events. Your scheduling process probably looks something like the following diagram.
Notice that the scheduling focus in the diagram above is on the air handler, rather than on activities that may or may not be happening in the rooms that it serves. The VAV boxes are scheduled based on the air handler’s schedule, again with no regard to activities that may or may not be happening in the rooms that they serve. Most likely, the air handler and VAVs are often running in empty rooms.
To truly take advantage of VAV boxes and HVAC equipment with variable speed drives, you need to be able to set them back to unoccupied whenever the rooms are unoccupied. To do that, you need to flip HVAC scheduling upside down.
Notice that rooms are now scheduled first, and VAV and air handler schedules are set based on activities that will actually be occurring in the rooms that they serve. If there are no activities in a room, the VAV that serves that room returns to unoccupied settings. If there are no activities in any of the rooms and all three VAVs return to unoccupied, the air handler will also revert to unoccupied or standby mode.
Of course this is not common practice because scheduling HVAC for each individual event in each individual room is much too time consuming. But in many types of buildings, someone is already scheduling each individual room for each individual event in order to allocate space. So why not use those existing schedules to drive HVAC schedules?
Events2VHAC event automation software pulls data from room scheduling systems and sends commands to HVAC controls to automatically return equipment to unoccupied settings between events. Zones can be created for equipment that serves multiple rooms, and if desired, you can trigger equipment only on the first and last scheduled event of the day. This strategy works well for large air handlers or exterior door locks. If occupancy sensors are already in place, they can be used to turn off equipment if no one shows up for a scheduled event.
This simple software integration is helping universities, K-12 schools, churches, convention centers, and government agencies across the U.S. and in Canada streamline HVAC scheduling, reduce energy use, and save money. Some examples are provided below:
University of North Carolina – Chapel Hill decreased electricity use related to cooling 33%, electricity use related to heating 16%, and chilled water use 29% in their student union with Events2HVAC – a 5-month ROI. (UNC Case Study)
Wicomico County Public Schools in Maryland cut HVAC scheduling time 99%. (Wicomico Case Study)
Washington State Department of Ecology expects to save 30,290 kWh of electricity and 64 Therms (a measure of natural gas) per year. (WSDOE Case Study)
Events2HVAC works with many commonly-used room scheduling systems. Check our Event Provider page to find out if we have an interface for your system.
Events2HVAC can operate as a BACnet/IP client, so if your HVAC system is BACnet/IP enabled, it should be compatible. We have additional interfaces for specific systems. Check our Device Interfaces page for more information.
If your room scheduling or HVAC controls system(s) is not listed, contact firstname.lastname@example.org, and we will check to see if an interface can be created for your system(s). We are creating new interfaces for customers as quickly as we can so that no one will be tied to one vendor.