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Is your HVAC System Proactive or Reactive?

Scheduling your HVAC system either proactively or reactively can have a huge impact on energy use and labor hours. For example, if you are running your whole building from 7 am to 7 pm regardless of whether or not each room is being used, you may be wasting a lot of energy in empty rooms. On the other hand, if you are manually scheduling your HVAC controls based on room schedules, you are saving energy but wasting a lot of time.

But what if you use occupancy sensors to automatically set empty rooms back to unoccupied settings in your HVAC system? That’s proactive, right?

Wrong. Occupancy sensors cannot predict occupancy, they can only react to it.

Occupancy sensors cannot warm up a cold room before an event begins; and they are often set to keep a room at occupied settings for 20 minutes after a room is empty. And what if someone comes back for a hat or jacket left in the room? That’s 20 more minutes of run time! Do you want to pay to heat a 300-seat auditorium when a student sits down to study for two hours between classes?

Consider the chart below. In which quadrant does your current method of HVAC scheduling belong?

Unless your building has a very high occupancy rate, you are wasting energy if you are running HVAC all day long in every room. If you have after-hours or weekend events, you may often have to come back to work to turn systems on for those events – sometimes unexpectedly. Though the labor of this reactive method is not intense all the time, it can be when you have to react to a phone call on a Saturday morning and miss your child’s soccer game. If you had Events2HVAC pulling room schedules and sending commands to your HVAC system, you wouldn’t miss that game.

If you are manually scheduling HVAC in a building automation system, you probably know exactly how many hours per week you spend entering schedules – and then changing them. And you also know how many hours per week you spend reacting to special circumstances or human error in the HVAC schedules. If your facility uses a scheduling software such as Microsoft Exchange/Office365, Dean Evans EMS, CollegeNet R25, or AsureSpace Resource Scheduler, Events2HVAC can pull schedules from it so you can focus on tasks that are more important.

But what about occupancy sensors? Don’t they provide the same proactive benefits as Events2HVAC?


Occupancy sensors have their purpose. They are great for turning on/off lights in spaces with unpredictable, intermittent use like bathrooms. But they are reactive, not proactive. Yes, you can certainly save energy with occupancy sensors, but they are not as sophisticated as Events2HVAC.

Events2HVAC can differentiate between setup time, event time, and teardown time so that different elements can become active with each trigger. You can also set a pre-start time to warm up a room before an event begins. For example, you can start HVAC 30 minutes before a scheduled event, turn on lights and unlock doors at the event start time, keep the room comfortable during the event, turn off lights and return HVAC to unoccupied settings at the end of the event, and lock the doors 20 minutes after the event is over. You can’t do that with occupancy sensors.

Events2HVAC also provides facility managers with a view into schedules set by others in the event scheduling software. You can check schedules live in the Events2HVAC client, and reports can be sent by email each day. Events2HVAC can also notify facility managers if a command is missed for any reason, such as a power outage, network problem, or equipment failure. Occupancy sensors cannot handle any of these proactive tasks.

Many of the facility managers we talk to are currently considering occupancy sensors for HVAC control. They may already have sensors in place for lighting, and they are getting good results, so they think they should use them for HVAC too. But before you jump into a premature – and reactive – solution, consider all the possibilities. Consider Events2HVAC event automation software.

Visit the Events2HVAC website to learn more about event automation. To request a quote or talk with a sales representative about your facility’s needs, please contact or call (888) 320-4277.


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