Designing a winning sports venue: HVAC systems
- Jerry Atienza, EIT, Senior plumbing designer, Interface Engineering, Portland, Ore.
- Douglas H. Evans, PE, FSFPE, Fire protection engineer, Clark County Dept. of, Development Services, Building Division, Las Vegas
- Todd Mack, PE, Principal, DLR Group, Omaha, Neb.
- Jeff Sawarynski, PE, LEED AP, Principal, M-E Engineers Inc., Denver, Colo.
CSE: What unique HVAC requirements do sports/entertainment structures have that you wouldn’t encounter on other structures?
Evans: HVAC systems may also be designed to provide smoke management functions. This can substantially complicate the HVAC design. The designers must determine if it is more cost effective to have a dedicated smoke management system, or if it should be combined with the HVAC system. In order to design the smoke management system, the expected fire size must be taken into account. If the design intends to keep smoke above head height to allow safe evacuation, this can further complicate the smoke management design.
Sawarynski: Very high turn-down rates for part load events must often be analyzed and the systems designed to accommodate that. Life safety systems are often integrated at a more granular level than in other building types.
CSE: What changes in fans, variable frequency drives, and other related equipment have you experienced?
Mack: We see increased use of direct-drive plenum fans arranged in a fan wall/fan array arrangement on many air handling units (AHU). The use of fan wall technology generally allows for a smaller AHU footprint in the AHU’s fan section. With a fan array there are more, small fans arranged in parallel airflow paths that move the air at slower rpm than a conventional single fan AHU. Slower rpm usually translates to quieter installation. Another benefit of the fan wall technology is the inherent fan redundancy.
Evans: VFDs are becoming common for controlling smoke-control fans. They provide the ability to adjust the air quantity to compensate for construction differences and time of year, and can be adjusted if needed as the building ages.
CSE: With regard to stadiums that have unique humidity challenges (ice arenas, pools, aquariums, etc.), how have you solved these challenges? What ventilation or dehumidification tactics have you specified?
Sawarynski: We have used cold chilled water systems (i.e., 35 F chilled water), energy recovery dehumidifiers that use compression cycles, and dedicated desiccant systems. Depending on the performance requirements of the building, any of these approaches may prove the correct approach.
Mack: We are currently designing the Breslow Ice Center in Lincoln, Neb. The primary function of an HVAC system in an ice rink is to provide dehumidification while providing fresh air for ventilation and spectator comfort. The dehumidification equipment we intend to specify will incorporate an enthalpy wheel to reduce the work required by the active desiccant dehumidification portion of the equipment and provide lower operating costs. Desiccant systems use adsorption or absorption to remove moisture from rink air. These systems can provide arena ventilation while delivering dew-point temperatures below freezing. Having both good temperature and humidity control in the arena helps to reduce sensible and latent heat gains to the ice surface.