Events2HVAC Blog

Occupancy Sensors vs. Event Automation

Nov 2

Written by:
11/2/2012 9:20 AM  RssIcon

The good folks at Dean Evans & Associates recently forwarded to me the article “Modern Efficiencies for Healthy Schools” by Adam VanOort. The article provides an overview of ways that K-12 schools, colleges, and universities are addressing energy efficiency of their campus buildings. The article is well-written, and largely focuses on the use of occupancy, temperature, and CO2 sensors in individual rooms to collect data and relay it back to the control system.

However, while sensors certainly have value in monitoring building performance, they are not be the best choice for actually controlling HVAC systems. Motion sensors work well for lighting because lights can be turned on and off quickly based on the sensor. But HVAC systems require more time to adjust. Therefore, using event automation software that controls HVAC based on event schedules is a better choice.

Event automation software is a fairly new concept. Though there were some custom solutions in place previously, the first commercially available event automation software, Events2HVAC, was released in November 2010. It is in use at 16 sites across the US to date, mostly colleges, universities and churches. It has some distinct advantages over using occupancy sensors in controlling HVAC systems:

  1. Installing occupancy sensors in each room on campus requires a lot of additional hardware, wiring, and technician hours. Events2HVAC is software, and usually requires no additional hardware or wiring unless a university needs to purchase a server to host the software. Usually purchasing a server is not necessary because the software can reside on the same server as their event scheduling software or another existing server on the same network.
  2. With Events2HVAC rooms will be comfortable when students, meeting participants, or wedding parties first arrive. With occupancy sensors it may take 20 minutes or longer depending on the room size for a room to get to a comfortable temperature. First impressions are important.
  3. Occupancy sensors will generally run HVAC another 20 minutes or so after everyone leaves. If someone comes back for a jacket left behind, or enters momentarily for some other reason, you can add another 20 minutes of runtime. Events2HVAC shuts down HVAC promptly according to schedule.
  4. With Events2HVAC there can be different temperature setpoints for setup and tear-down periods for larger events (concerts, conferences, trade shows, etc.).  You can’t do that with occupancy sensors.
  5. Occupancy sensors cannot control security (electronic door locks) – and you wouldn’t want them to! Events2HVAC can send commands to JCI P2000 security systems and systems that are BACnet compatible so that rooms are only accessible at scheduled times. This can cut down on college classrooms being used for other purposes such as eating lunch and socializing between classes, resulting in less cleanup for janitors.
  6. With Events2HVAC, facility managers can receive an email report each morning showing all the events scheduled for the day and the commands that will be sent to the building automation system. Facility managers also receive an automatic email message immediately if a command does not execute for any reason (power outage, equipment failure, etc.). Occupancy sensors don’t produce reports or send out alert messages without additional programming.

Yes, sensors can help facility managers monitor their buildings and identify energy efficiency opportunities. But Events2HVAC automates energy efficiency, freeing the facility manager to do other tasks. Colleges and universities should invest in event automation software first to cut their energy and HVAC scheduling expenses significantly campus wide, and then consider which spaces need sensors for continuous monitoring, data collection, and analysis.

About Us

Founded in 1998, Streamside Solutions provides software products, solutions and services for the building automation industry.

Phone: (888) 320-4277



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