Over the past decade, many convention centers and event venues across the United States have sought to distinguish themselves by “going green.”  Adopting environmental and energy friendly practices not only reduces utility & maintenance costs, but has served as a key marketing tool for attracting clients and events to their venues.  To this goal, numerous sites have pursued LEED and Energy Star certifications.  Solar panels and rain-water collection tanks have been great marketing tools for these facilities and set in motion the desire to keep improving.  However, when owners want to go beyond bike racks, recycle bins, and upgraded lighting, they are often presented with the difficult task of understanding how their facilities actually use energy.

For many building owners, energy models have served to help engineers and staff understand their energy consumption and evaluate energy and cost savings alternatives.  However, event venues are arguably the most difficult type of facility to properly evaluate with energy modeling tools.  It can be difficult for an owner or energy service company to find energy modeling teams experienced enough to understand and solve issues surrounding this type of building model.

A core assumption made for 95% of building energy models is that “consistent occupancy patterns” exist.  This is something that many event facilities just don’t have.  From year to year and month to month, occupancy of an event facility’s rented spaces (often the majority of the building) change based on state of the economy, effectiveness of the facility’s marketing staff, and the attractiveness of the location, more than on any other predictable factor.  This introduces a major challenge for energy modelers, as occupancy in event venues is often the most important factor in determining facility energy consumption.  Event occupancy can affect almost every building energy system including the HVAC systems, the lighting, hot water use, and even plug loads.

On top of occupancy uncertainty, event venues can often have unusual building geometry, multiple additions with multiple building utility meters, complex HVAC systems, and staff who are often more concerned with ensuring client comfort than optimal energy usage.  These things combine to make these type of facilities some of the most difficult to accurately model.  Even if all these variables can be handled properly, it can be difficult to justify model accuracy with utility data since future occupancy can be significantly different than modeled occupancy based on past trends.

Griffith Engineering has answered the riddle on how to deal with the constantly changing occupancy in Building energy models.  GEI has successfully created accurate energy models that not only use real historical weather data, but can also account for individual events on a day to day basis.  This allows occupancy, as a variable, to be isolated so other energy consumption variables can be identified and quantified.  The process results in high quality energy models of event facilities that can provide an accurate picture of how proposed building improvements and upgrades will affect the energy consumption.  Additionally, the process developed by GEI’s energy modeling team can be used to assist in measurement and verification requirements by ensuring future changes in event occupancy are properly accounted for energy savings calculations.

GEI is currently involved in applying these techniques for one of the largest convention centers in the nation.  Also check out these other projects where we have applied these techniques: