The art of designing sports, entertainment, and specialty structures: Sustainability, energy efficiency

Entertainment venues are big businesses—and big on complexity, with a host of complex systems and requirements for engineers to tackle such as sustainability, green building, energy efficiency, and net zero buildings.

By Consulting-Specifying Engineer August 25, 2017

Respondents

  • Steve Brown, Certified Automation Professional Vice President and Operations Director, Energy & Automation Teams Environmental Systems Design Chicago
  • Daniel P. Christman, PE, LEED AP Vice President/Entertainment Market Sector Leader exp Orlando, Fla.
  • Keith Esarey, PE, LEED AP Principal McClure Engineering St. Louis
  • Tony Hans, PE, RCDD, LEED AP Vice President CMTA Louisville, Ky.
  • Mike Hart, PE, LEED AP Principal, CEO ME Engineers Golden, Colo.
  • Doug Lancashire, PE, LEED AP, CEM, CGBE Vice President, Director of Energy/Facility Systems Osborn Engineering Cleveland
  • Chris Skoug, PE, CEM Principal Engineer Southland Engineering Dulles, Va.  

CSE: What unusual systems are owners requesting that help save energy and/or electricity when a space is unoccupied?

Hans: We have implemented two "nontraditional" system features to improve indoor-air quality while also saving energy. The first system feature uses ionization technology. The units assist in the reduction of volatile organic compounds, sterilization of bacteria and mold, reducing odors, and reducing particle sizes (particulate matter). These devices are generally installed in the air handling equipment including DOAS. There are many manufacturers in the marketplace that offer this type of product. The second technology is carbon dioxide scrubbers with regeneration technology. This device allows for excellent indoor-air quality, reducing CO2 and ozone while also reducing the overall ventilation requirements for the facility.

CSE: Energy efficiency and sustainability are frequent requests from building owners. What net zero energy and/or high-performance systems have you recently specified on specialty facilities?

Skoug: It would be hard to imagine the design of a very large stadium being able to achieve net zero energy unless there was a significant renewable energy feature. Otherwise, standard HVAC and lighting improvements are generally used to offset losses from low-performance building envelopes (as compared with the baseline building).

Hans: With more than a dozen zero-energy facilities designed and more than 1.2 million sq ft of zero-energy spaces in operation and construction, we have used many different systems for many different building types. The process is typically the biggest surprise to the owner and the rest of the design team. Zero energy is a performance goal and is achieved through a process, not a product or system type. For most zero-energy projects, the goal of drastic energy reduction is only achieved through creating paradigm shifts within the design team and owner’s staff. Getting people to not design or use a facility as they always have in the past is crucial. We often take trips to other zero-energy facilities we have designed or create peer-to-peer connections between groups, such as information technology, maintenance, or food service. Finally, we strive to shift costs so that the goal can be achieved with minimal effect on the budget.

All of our zero-energy facilities met drastic energy reduction within budget (surprising, but it does not cost more to use drastically less energy). We are most proud of two very recent projects where large (60,000- to 100,000-sq-ft) facilities met their zero-energy design goal while remaining under their budget for a similar non-zero-energy facility, including adding the renewable photovoltaic (PV) solar array. Solar PV costs have dropped so low that cost shifting and team collaboration can go a long way to minimizing the size of the array, making it such a small percentage of the budget that it becomes achievable without additional funding. Prioritization of the zero-energy goal is fundamental. Here is the live performance of a recent project that produced more energy than consumed for the 2016-2017 year.

CSE: What types of sustainable features or concerns might you encounter in such a facility that you wouldn’t on other projects?

Esarey: One area of concern we encounter is the height of the structure. Specialty structures tend to be very tall. Acoustical projects often involve large-volume spaces. This means that shading does not really become a factor. When properly designed, a system will not have to precool. This, again, leads to energy efficiency and cost savings.

Christman: Tied in with guest experience and comfort for sports arenas and theaters, schedules for events don’t follow a typical 9-to-5 office occupancy/time frame. This gives the perception that optimizing schedules for these facilities is difficult. We see many buildings with HVAC equipment in manual mode, overridden from the controls system, so that it remains on to maintain a temperature setpoint in the space. This is, of course, a tremendous waste of energy. The concern for this can be eased through education of the building operators. While one may not be able to automate each system to match the exact events schedule, you can put into place a facility management plan that describes "preheating/precooling" a space as "X hours before an event." This helps eliminate 24/7 operations and saves energy.

Lancashire: The biggest challenge in meeting sustainability goals on a sports project is in the energy consumption associated with large ventilation requirements. Using energy recovery, demand ventilation, and/or bipolar ionization to reduce outside air are critical strategies to reduce energy usage in such facilities.

CSE: What types of renewable or alternative energy systems have you recently specified to provide power for such projects?

Hans: Working with multiple utility companies has taught us that the rules and laws are different for each. Net-metering rules are not only different in each state, but also vary within utility companies in the same state. Many utility companies require grid-connection studies. Another challenge has been with specifying products. Once a project has bid and materials are ready to be ordered, they are either obsolete or not available. We have written in performance requirements stating that if materials are obsolete, the contractor must provide a solution that is equal or better than the original basis of design.

Skoug: Rainwater harvesting from large roof surfaces and plaza areas is very achievable. The NFL stadium uses an 800,000-gal cistern for stormwater capture from the roof and elevated plaza surfaces. This reclaimed water is used for both cooling tower make-up and site irrigation.

Christman: As PV systems are becoming more efficient, we are seeing the use of local or central PV systems (i.e., multi-acre PV farms) that feed back into a building or parkwide infrastructure. Another popular way to use PV is in open parking lots where the inverters are tied into the electric car-charging stations. We are seeing paybacks for systems like this in the range of 4 to 5 years.

Lancashire: For one major league ballpark, we designed a PV array on the roof of a picnic pavilion out on an upper-level concourse. Fans can go online and watch how much power is being produced from the array at any given time.

CSE: What are some of the challenges or issues when designing for water use in such facilities? What types of low-flow fixtures, water reuse, or other techniques have you designed?

Hart: High-occupancy performance-based facilities like stadiums, arenas, and theaters have their own restroom-use patterns that must be taken into account. Water use will peak at intermissions, but will also hit highs as the facility fills up and as the shows wind down. We have metered a number of venue types during peak events like a World Series or Superbowl game. This information acts to inform and confirm our own peak-use estimates so that piping and booster pump systems are properly sized. The wider acceptance of flushless urinals in public facilities has acted to somewhat reduce those peaks.

Skoug: Examples of water-usage-reduction strategies for previous stadium design include rainwater harvesting, low-flow plumbing fixtures, and flushless urinals.

Christman: Guest experience and maintenance issues are always the top two concerns with owners when they think "low-flow fixtures" in these types of facilities. Will the guest "feel less water" to wash their hands? Will a low-flush toilet really hold up to the number of visitors expected for an event? In sports venues, water savings from the use of low-flush and low-flow fixtures can be significant for an owner. Low-flow water closets have been used successfully in many sports arenas. LEED plaques are showing up on many newly constructed facilities. Efforts to "green" existing facilities also have been a recent trend in the industry as LEED for Existing Buildings is becoming more popular. For new construction, a minimum potable-water-use reduction of 20% is required. The simplest way to achieve this is through the use of reduced-flow-rate fixtures.