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Northwestern University Automates Arena Ventilation Based on Event Schedule

Northwestern University had a problem. The newly remodeled Welsh-Ryan Arena’s HVAC needs varied with different types of events. For a basketball game, maximum ventilation was needed for the large crowd. For basketball practice and other smaller events, less ventilation was needed.

Since they are using Events2HVAC to automate HVAC based on scheduled events in the arena and other buildings on campus, Northwestern contacted us at Streamside Solutions to help solve their problem.

Our solution is a new custom multi-state action in Events2HVAC that permits event schedulers to trigger predefined states from metadata in each event in their room-scheduling system (Ad Astra, EMS, 25Live, etc.).

In Northwestern's arena situation, they wanted to control the number of air handlers enabled for the arena based on the typical size of the crowd for an event. In 25Live, they created special event types for typical venues: Small Athletic Event, Practice, Medium Athletic Event, and Large Athletic Event.

In their JCI control system, they created a multi-state point for the mode of the arena that represents the "Game Mode". This mode would determine how many air-handlers would be enabled for the event based on the table below:


Event Type

Game Mode

HVAC State






"Small Athletic Event" or "Practice"




"Medium Athletic Event"




"Large Athletic Event"




<Any other Event Type>



The arena has 4 ahus that serve the "seating bowl". They use the mode point to stage the fan systems according to the event crowd size. If it is a small event such as a practice, they run a fan on each side at a reduced static setpoint. For a medium event such as a women's game, they run four fans at a reduced static setpoint. For a large event such as a men's game or a concert, they run all four at normal static. In addition, they also use E2H to enable the locker room ahu when any mode is initiated.

The custom multi-state action has an expression editor that allows a user to create the conditions from the event needed to generate each state command. You can even give each state a "rank" so that overlapping higher priority events can be initiated while another less important event is in progress.

"It works really well. The athletics staff schedule their events weeks ahead of time via our 25Live system and E2H picks it right up!" - John Hoegerl

Now, the event planners can transparently schedule the occupancy of the AHUs AND the the correct AHU operating sequence just by setting the appropriate event type in the event.

The custom multi-state action solved Northwestern’s problem. But it can do much more. Here are some additional ways it could be used:

  • Changing lighting levels based on the type of event.

  • Changing percent ventilation based on the expected attendance of an event.

  • Shutting down equipment when a utility company notifies the organization of an upcoming demand response event or peak energy day.

  • Commanding special setpoints in the room when certain event names are scheduled.

Events2HVAC users will certainly think of more ways to use this new feature, which is now available in v1.6.3 and later.

For a good look at the newly remodeled Welsh-Ryan Arena, check out this video posted by Northwestern Athletics:


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