Tarrant County: Energy efficiency is paramount
The owner of the Tarrant County College District (TCCD) Energy Technology Center (ETC) in Fort Worth, Texas declared: “Energy efficiency is paramount.”
In a facility dedicated to energy-related technologies, it makes sense to make energy efficiency a top priority in the design. The ETC will house the Heating, Ventilation, Air Conditioning and Refrigeration (HVACR) Program along with workforce training programs for jobs related to the oil and natural gas industry, government energy efficiency initiatives and renewable energy technologies. As the first new building on the TCCD South Campus in over 30 years, the building represents an incredible opportunity to showcase innovative design and set the tone for future development.
The first move toward energy efficiency was to orient the building on site to optimize its relationship with the sun. A standard strategy to effectively use daylight instantly became one of the first roadblocks to navigate. The existing buildings on the South Campus are laid out on a grid rotated thirty degrees off true north. Although the client was amenable to allowing the ETC to sit along a different alignment, the building needed to fit into its context and relate to the existing campus.
After several iterations of the site layout, a dominant east-west axis was created for the two buildings that make up the ETC. A kink in each building shifts the eastern portions toward the campus grid and pedestrian approach. The minimal increased exposure to the morning and afternoon sun on those facades can be mitigated by the treatment of the building envelope. The resulting design addresses the campus entry, improves pedestrian access and creates a sheltered courtyard between the two buildings – a new destination for campus life. The layout acknowledges adjacent buildings while making a strong statement about a new approach to design on campus. It denotes the building as a teaching tool and provides a visual cue that this building has a story to tell.
To capitalize on the natural light available as a result of the building orientation, the majority of glazing faces north and south. Limited openings on the west facades lessen the impact of the hot afternoon sun. Examining the window areas at north and south elevations with daylight modeling software helped inform the height of the clerestory and placement of view windows. Solatubes in each classroom bring natural light deep into the room to supplement the daylight coming in from windows. Nearly all classrooms, labs, corridors and gathering spaces will be fully lit with daylight. Sensors control the light fixtures to dim or turn them off when natural light is sufficient.
What makes this building unique are the fourteen lab/workshop spaces specifically tailored to the instructional programs. One lab contains twenty welding booths. Another lab contains twelve residential A/C units next to an adjacent lab with the corresponding twelve condenser units. In another, there are assorted ice machines, freezers and pie cases. Ambient temperatures in each lab may fluctuate widely as equipment is tweaked and tested by the students. A tight building envelope would allow good control of the interior temperatures and less stress on the building mechanical systems. However, the functional need to move large equipment and materials in and out of lab spaces threatened to cut giant holes in the building skin and compromise the ability to regulate interior temperatures. Faculty requested overhead coiling doors, each twelve feet wide by twelve feet high, to permit delivery and removal of large items by forklift.
In reality, deliveries by forklift were found to happen only once or twice a year. The team suggested placing the overhead coiling doors on the inside of the building. Eight labs would have an overhead door facing the interior corridor, which became the route for delivering materials. What would have been eight large exterior openings were reduced to two — one at the end of each corridor. The corridors were widened to accommodate a forklift carrying materials, glass was specified for the overhead door segments and multiple benefits resulted. In the wider corridors there are computer workstations, student lockers and tables for individual study or group work. Furnishings can be moved around during events or material deliveries. A group can gather outside a lab to view equipment through the glass doors without disturbing the class inside. Mechanical rooms with large windows also face the corridors, exposing the building mechanical systems for additional real-time learning opportunities.
Locating rooms with similar heating/cooling strategies together garnered additional energy efficiency. When coupled with strategies such as continuous insulation, reflective roof, using campus-supplied chilled water, heat transfer and energy capture from lab equipment, sub-metering and building monitoring systems the facility meets its design goal for energy reduction. All strategies were tested in an energy model throughout the design process.
Exposed structural, mechanical, electrical and plumbing systems will adorn the interior of the ETC. Occupants will observe parallel pipes and ducts snaking along the corridor ceilings, branching off into rooms as needed. Within labs and classrooms faculty will instruct students in fabricating duct work, installing electrical wiring and repairing HVAC equipment, while the building around them teaches its own lessons on energy efficiency.