LEED-ing the Way

Mar 16, 2022 | News

Ghafari is leed-ing the way in sustainable building design with the O'Hare Modernization Program, which reimaged the ARFF Station.

The O’Hare Modernization Program offered an opportunity to reimagine a state-of-the-art Aircraft Rescue and Fire Fighting (ARFF) Station to fulfill both airport rescue and structural firefighting needs in one location. Negative environmental impact in the aviation industry originates from both aircraft and ground infrastructure operations. Consequently, the Chicago Department of Aviation (CDA) prioritized high environmental performance and sustainability strategies for the development of this new station, targeting certification under LEED NC 2009. Our integrated design and delivery approach was key in meeting these goals from project inception to post-occupancy.

From schematic design through design development, opportunities to achieve synergies across disciplines and building systems were researched and identified. Natural systems for lighting, ventilation, and passive heating and cooling were prioritized before mechanical systems were considered. Early energy modeling helped make informed design decisions by quantifying the impact of several parameters on overall energy performance. Comparative analysis for massing and orientation, exterior lighting, building envelope, indoor thermal comfort range, interior surfaces reflectance, lighting levels, and process loads reduction options were conducted.

The building form features multiple recesses, with glazed apparatus bay doors and a skylight inviting natural sunlight inside, reducing the need for artificial lighting. The facility includes Energy Star-rated PVC roofing with an SRI of 80, high-performance Low-E insulating glass, and thermally broken storefront frames. A thermally efficient masonry and rainscreen envelope wrap the building, and with sun-shading louvers, enfolds an exterior recreational patio. The hose tower service wing adjacent to the apparatus bay and the curved penthouse is clad in a silver metal panel, distinguishing support spaces from the masonry rain screen envelope.

Interior lighting is controlled with an automatic device that will turn off the entire building’s lights. The automatic functions are on a programmable schedule, occupancy sensor, or signal from another control system. All exterior lighting is provided with full horizontal cutoff lenses, controlled through an automatic control system.

From schematic design through design development, opportunities to achieve synergies across disciplines and building systems were researched and identified. Natural systems for lighting, ventilation, and passive heating and cooling were prioritized before mechanical systems were considered. Early energy modeling helped make informed design decisions by quantifying the impact of several parameters on overall energy performance. Comparative analysis for massing and orientation, exterior lighting, building envelope, indoor thermal comfort range, interior surfaces reflectance, lighting levels, and process loads reduction options were conducted.

An energy recovery ventilation (ERV) unit, equipped with a Total Energy recovery wheel, was provided to feed pre-conditioned outside air (OA) to air-handling units (AHUs). The energy recovery wheel limits recirculation of air from leakage, carry-over, or transfer from the exhaust stream to the supply stream to less than 10% of the OA intake flow. The air systems’ sequences of operation include economizer cycles that take advantage of favorable OA temperature and humidity levels, allowing HVAC refrigeration and heat rejection systems to shut off. Variable frequency drive (VFD) motor control systems supply fans in the AHUs and make-up air unit (MAU) to conserve energy by reducing fan and motor speeds when HVAC loads were below their design maximums.

A complete BACNet-based direct digital control system was used to automatically control, monitor, and trend HVAC system data, allowing for educated adjustment to maximize operational efficiency. The Building Management System (BMS) can tie into the open-protocol Energy Management Control System currently being installed in other airport buildings. The BMS monitors all HVAC equipment and is configured to trend and record daily energy usage.

Energy efficiency features include heat traps on the inlet and outlet piping, and a closed combustion chamber. Energy Star® labeled hot water heaters were used, meeting thermal efficiency and standby loss requirements of the U.S. Department of Energy. Thermal efficiencies are 95% and higher.
Integration of the new facility’s utility networks with the existing site utilities was established. Infiltration trenches and grass swales manage stormwater. High-efficiency, low-flow plumbing fixtures reduce water consumption. The landscape uses native or adaptive grass requiring no permanent irrigation systems, further reducing potable water demand.

Sustainable construction practices were adopted to comply with CDA best practices. Clean fuel construction vehicles such as off-road diesel-powered vehicles and construction equipment maintenance activities – including vehicle washing, maintenance, fueling, chemical storage, and spill control – were used to minimize air quality impacts.

Natural light in the apparatus bay and improved indoor air quality increase job satisfaction, health, and preparedness of the rescue/firefighting crew. While no direct access to mass transit is provided on-site due to mission constraints, the 45% reduction of parking spaces, compared to The Institute of Transportation Engineers ratios, contributes to less traffic congestion for surrounding communities.

The overall design, construction, and operation of the facility reduces greenhouse gas emissions, conserves water and natural resources, and improves first responders’ well-being and preparedness. The ARFF is a model of sustainability for other O’Hare facilities and may lead to benefits extending beyond the workplace and result in increased applications of sustainable design and behavioral change in the community at large

This article, written by Ghafari, was originally featured in The Source.

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