ASHRAE Journal - May 2011 - 37

technology award case studies
Building at a Glance
Name: Ann Arbor Skyline High School Location: Ann Arbor, Michigan Owner: Ann Arbor Public Schools Principal Use: comprehensive high school Employees/Occupants: 1,600 students Gross Square Footage: 380,450 ft2 Substantial Completion/Occupancy: Summer 2008 National Distinctions/Awards: LEED Silver Certification, 2009 Engineering Society of Detroit, 2008 Build Michigan, Sierra Club Conservation, WCA Pyramid, 2009 Learning by Design, American School and University.

South-facing large box spaces including gymnasiums, auditorium, and natatorium. opened in 2008 for ninth grade students and currently operates with ninth through eleventh grades. Among the guiding design parameters was to deliver a state-of-the-art facility that minimized impact on the environment and maximized energy efficiency and sustainability. The use of an energy model early in design (using nationally recognized energy simulation software), enabled the team to collaborate on optimum design solutions such as building orientation, fenestration options, roof and wall types, and mechanical systems. The partnership between the professional design and construction team, the school district and the community members resulted in a highly functional building that operates comfortably and efficiently. Key to the achievement of LEED Silver certification was the Energy and Atmosphere credits received due to the energy-efficient nature of the building systems. Under LEED-NC2.1 the building was awarded seven points under EA Credit 1, demonstrating a 44% energy savings over the standard baseline of ASHRAE/IESNA Standard 90.1-1999. The building was designed to accept the mechanical systems with a fifth floor penthouse along the length of the classroom tower. Small unitary water source heat pumps line the sides of the penthouse and have short duct runs down to the classrooms below. Each space has individual temperature control along with occupancy setbacks and carbon dioxide
May 2011

monitoring. Four dedicated outside air units with air-to-air plate energy recovery and integral water source heat pumps provide neutral 60°F (16°C) ventilation air to each unitary heat pump system. Return air is mixed in the penthouse and relief air is sent though the energy recovery units. The ventilation air is measured and controlled by pressure independent variable air volume (VAV) boxes and modulated based on feedback from the space mounted carbon dioxide sensor and occupancy. The range is in compliance with Standard 62.1-2004 and provides the correct volume of ventilation air to each room. The dedicated outdoor air system’s (DOAS) supply and exhaust fans include variable frequency controllers in response to the variable air volume box requirements.

Large spaces such as the gymnasiums, cafeteria and auditorium are served by single zone energy recovery units with air-to-air plate energy recovery devices to pretreat the ventilation air and integral
DPT

Main Building Pumps Geothermal Field Field Bypass VSD

HPLS HPLR Two-Way Control Valve

Dedicated Outdoor Air System Outside Air Plate HX COIL Relief Air EF Integral Heat Pumps SF VSD Ventilation Air at 60°F VAV 0, 125 – 450 cfm Return Air Supply Air To Classroom

SF Heat Pump

T CO2

Figure 1: The building is heated and cooled by water source heat pumps.
ASHRAE Journal 37

ASHRAE Journal - May 2011

Table of Contents for the Digital Edition of ASHRAE Journal - May 2011