As sustainability becomes an even higher priority for design and construction, buildings that have historically consumed large amounts of energy and water, such as campus recreation centers, are subject to a sustainability overhaul.
Certain design approaches emphasize sustainability. For instance, the LEED Platinum certification has become a standard for sustainable projects. At the same time, when there are stringent requirements, project teams seek to employ innovation. In one case, the California State University mandated no mechanical cooling aside from dehumidification in buildings like natatoriums.
The following 12 approaches offer creative considerations to optimize energy and water efficiency and reduce annual costs.
12 Key Approaches
1: Optimize building envelope materials and shading structures to reduce energy consumption, increase occupant comfort, and improve daylight access. The Mashouf Wellness Center (MWC), San Francisco State University relies on fins and overhangs that provide functional shading as well as a crisp, contemporary, fluid aesthetic.
2: Incorporate sustainable insulation solutions. To minimize the impact of not having mechanical cooling, R-19 walls with rigid exterior insulation and an R-32 high reflectance roof, along with high performance low e-glazing, were used at the MWC.
3: Integrated low-impact mechanical systems provide heating and cooling in fitness areas at the University of Oregon’s Student Recreation Center in Eugene. Heat recovery and displacement ventilation, chilled beams, and radiant slabs for heating and cooling reduce systems’ footprint while prioritizing occupant comfort.
4: An energy recovery coil captures heat from the space exhaust, reducing the required heating load. For a natatorium, the supply air temperature can be maintained at 2°F above the temperature of the main pool, decreasing the amount of evaporation from the pool surface and thus reducing the need for dehumidification.
5: High-efficiency lighting design that incorporates all LED lights as well as daylighting controls and occupancy sensors can achieve significant reductions in lighting energy. Creative solutions, such as solar tubes in large gym spaces, increase the available daylighting in spaces with deep floorplates.
The Beauchamp Recreation and Wellness Center at the University of Portland uses LED lighting as a replacement for all fluorescent lights. This solution incorporates digital lighting controls that allow for demand response and reduced lumen maintenance throughout the building.
6: Displacement ventilation systems maximize the amount of “free cooling.” Displacement systems provide uniform temperatures within occupied zones and increase the required supply air temperature. This dual functionality reduces the number of hours the space will be above the cooling setpoint. Natural and displacement ventilation of the gym, lounge/recreation area, and cardio/weights area was a key sustainability feature of the Health and Wellness Center at Western Oregon University in Monmouth. In a moderate climate, this type of strategy provides occupants with substantially more outside air than in a building where the air systems are sized for minimum ventilation only.
7: Additionally, simple ceiling fans help to increase the occupant thermal comfort. To ensure the air circulated by fans is clean before it enters the space, air handling units can be provided with a high level (MERV 13 or above) of filtration.
8: Uniform air ventilation integrated with the ceiling provides consistent temperatures and energy expenditure. Along the interior perimeters of a building, a small gap for return air between the ceiling system and the wall creates unique return air flow, while also allowing for easy plenum access when necessary.
9: A supply air distribution system design purifies interior air. High and low supply distribution can capture odors, such as chlorine, and contaminants at their point of settlement by surface washing the pools at the water level. This maximizes air quality within the space (low supply air) and washes windows, ensuring windows do not experience condensation (fogging), which is typical of many natatoriums with poor HVAC design.
Such temperature, humidity, and ventilation controls can stand up to the rigors of even the most sophisticated aquatic centers. At California State University’s Maritime Academy, for example, the physical education complex includes a natatorium with a wave generator, capable of simulating aquatic survival situations, lifeboat drills, and scuba instruction.
10: High and low exhaust air can also limit chlorine settlement as well as evacuate contaminants at the exposed structure to ensure structural systems do not rust over time.
11: A water recovery system is cost neutral and can take advantage of existing infrastructure. Water conservation is important to increasing efficiency, as recreation centers are known for their high water usage levels. To reduce consumption, backwash water from the pool, as well as greywater from showers and lavatories, can provide 100% of the non-potable water used for flushing toilets and irrigating sports fields on the site.
Using these practices at MWC, as well as harnessing the efficiency dual plumbing due to current regulations in the building’s zoning, an estimated 334,000 gallons of water is saved, cleaned, and used as irrigation for the surrounding ecological zones in one year. Low flow fixtures, including lavatories with 0.35 GPM aerators and pint flow urinals, were also used.
At the Portland State University Academic and Student Recreation Center, rainwater is harvested and stored in a collection tank that doubles as a source for flushing toilets and emergency fire suppression.
12: Jurisdictions that require dual plumbing can provide an advantage in designing for future non-potable water connections. Since this piping is already required, greywater treatment systems can utilize this piping instead of waiting for the municipality. The budget for such a design is about the same as that of a standard project and uses an integrated design process to get the most advantageous systems without adding cost.
Cost Effective Design Contributes to the Bottom Line
When educational leaders and project teams examine the factors that add up to the total cost, an energy- and water-efficient facility can be created at little additional cost compared to a facility only meeting basic zoning requirements. Integrated design is the critical first step: optimizing the building’s envelope, lighting, mechanical, and plumbing systems can significantly reduce the consumption of fossil fuels and water.
Other cost savings can come from photovoltaic systems, which can further reduce a building’s energy consumption while also generating a percentage of the energy it uses. With enough design consciousness, a project can even achieve LEED Platinum certification. At MWC, under Version 3, the facility achieved 55.6% annual energy cost reduction over the ASHRAE 90.1 baseline, reducing greenhouse gas emissions by 828 Metric Tons. This equates to the annual electricity use of 71 homes or 53,115 gallons of gasoline.
For the 118,700 sf MWC, these outcomes spoke to the underlying institutional mission to “promote positive physical and mental health, encourage lifetime interest in active, healthy lifestyles and provide student leadership opportunities that complement the academic experience.”
By employing practices that are mindful of the building’s environmental footprint and emphasize sustainability wherever possible, design teams can still meet the considerable demands of users and stay within the parameters of the defined budget. The increased efficiency of such a design will contribute to the bottom line long after construction is complete, making for even more substantial savings in the long term.
Article originally published by American School & University, October 9, 2019.