Haywood Community College Creative Arts Building: Clyde, N.C.
Crafting Energy Solutions
Creativity flourishes here. In bright, open spaces conditioned by the North Carolina mountain air, nimble hands craft clay, wood, fibers and metals into one of a kind works of art.
The new home of the internationally acclaimed Professional Arts program at Haywood Community College is designed to inspire artists’ creativity. Instead of making the best of the former cramped, rundown facility, artists now create their crafts in open, well-designed spaces with lots of light. The move has attracted new students to the program and increased the quality of students’ work.
But, pottery studios where toxic glazes are used require extensive indoor air quality measures, the detailed work of jewelry making and weaving demands enhanced lighting levels and a dust collection system is critical to ensuring safety in a woodworking shop. Creative design solutions to these challenges were found in largely passive designs tailored to the needs of each space.
Energy efficiency, passive heating and cooling, daylighting, solar thermal heating and cooling, and photovoltaics reduced the first year’s energy consumption from the national Commercial Buildings Energy Consumption Survey (CBECS) energy use intensity (EUI) average of 120 kBtu/ft2•yr to a gross EUI of 33.4 kBtu/ft2•yr and a net EUI (after solar photovoltaics) of 21.7 kBtu/ft2•yr.
The 41,000 ft2 facility is designed to accommodate the college’s growing clay, jewelry, wood and fiber programs for full-time students and associated night classes for continuing education students. The three-level building that steps down a heavily wooded, south-facing hillside opened in March 2013.
The college wanted the Creative Arts Building to demonstrate the college’s commitment to sustainability. And, the goal was to achieve energy- efficiency levels commensurate with the 2030 Challenge objective of at least a 60% energy reduction, or a net (after on-site renewable energy) EUI of 36 kBtu/ft2 • yr or less despite several challenges:
- Similar existing facilities consume 120 kBtu/ft2•yr;
- The ASHRAE Standard 90.1-2007 baseline is 91.6 kBtu/ft2•yr;
- Curriculum-required equipment loads were projected to account for over half the building’s energy use;
- The building has extended hours of operation; and
- The site is difficult for solar access.
The team also decided to design the building to LEED Platinum standards. Plenty of challenges existed for this goal as well, including high water demands, extensive runoff from the rest of the campus, and numerous energy and air quality challenges posed by nine electric and three gas kilns, pottery glazes, paint and soldering booths, woodshop equipment and an array of power tools.
A key objective was to retain the rural campus character and improve pedestrian ways by implementing a design that saved existing vegetation and harmoniously fit into the rolling mountain site. To preserve and enhance natural site features, the building conformed to the sloping site, creating three, stepped east-west oriented wings that facilitate solar access, daylighting and natural ventilation while retaining as many trees as possible. The stepped approach also met another objective by providing ground-level access to all of the facility’s studios.
To improve the site’s water quality, campus storm water is treated via sand filters, a constructed wetland pond and bioswales. These measures reduce pollutants from the storm water runoff, recharge the aquifer and replenish local mountain streams with cleansed water.
Stack ventilation shafts allow for natural ventilation of the lower-level studio spaces. Outside air enters through the operable windows, rises through the shafts and exits above the rooftop.
Haywood County is located in the mountains of western North Carolina, has sunshine 59% of the time (1.36 kBtu/ft2•yr global horizontal) and receives 48 in. of rainfall that comes rather uniformly throughout the year. While the average annual temperature is 55°F, temperatures have ranged from 100°F to 16°F.
Energy demands are predominantly driven by heating. From purely a degree-day perspective, heating outweighs cooling by 85% to 15%. However, due to the anticipated extremely high internal loads, actual demand for supplemental energy shifted to 60% heating and 40% cooling.
Selecting energy strategies started with addressing energy efficiency. Creating a high-mass, well-insulated building shell provides lag time and energy storage benefits, and increased comfort and durability. Exposed interior mass in the walls and floors plays a significant role in retaining thermal stability despite the high levels of ventilation required for many spaces. The berming of the two lower wings, through contact with the earth, also provides significant thermal benefits.
High-performance, low-e glass is used for all of the lower view windows while upper daylighting aperture selection was dictated by orientation (south or north) and the functions occurring within each space.
Radiant roof loads are minimized through the use of ENERGY STAR-labeled metal roofing panels and white membrane roofing. In addition, the majority of the roof is covered with solar panels and modules.
Given the predominant heating load, south-facing glazing strategies are implemented to maximize daylighting and passive heating benefits. Lightshelves are placed immediately below the daylighting glazing areas and above the view glass on the south, which enhances daylighting and helps shade the lower view glass in warmer months.
Controlled daylighting is a key strategy in reducing energy consumption and improving indoor environmental quality. More than 85% of the facility’s regularly occupied spaces maximize daylighting by providing superior light levels during two-thirds of the daylit hours. A variety of strategies are used to address varying demands including:
- Fiber-filled south glazing with exterior lightshelves;
- North clerestories with clear glazing; and
- Roof monitors.
Because of the types of tools and equipment used in the studios, it is critical that the strategies used be glare free, eliminating all direct beam radiation and routinely producing the high, 75 to 100 footcandle levels required for acute visual tasks. Supplemental light levels in all daylit spaces are controlled by daylighting sensors that automatically dim energy-efficient light fixtures to optimum levels.
“I have said repeatedly to the press and visitors that I’ve already experienced a change in the quality of our student’s work — I attribute this to the many ways that the building works splendidly, especially the quality of light and the well-designed spaces,” said Terry Gess, Chair, Professional Arts, Department of Creative Arts, Haywood Community College.
High, north-facing glazing provides superior daylighting in the classroom and studio spaces located on the north side of the three wings.
To maximize the potential for natural ventilation, operable windows (motorized on the high north side) are placed throughout the facility, and north side stack ventilation shafts extend from the lower-level shop areas to high above the second-floor levels. These shafts allow for fan-assisted and natural ventilation options with outside air entering through the operable windows, rising up through the shafts and exiting high above the rooftop. The fan-assisted ventilation option is manually initiated (via a switch) and automatically turns off the mechanical system.
Two main dedicated systems that serve the entire building induce fresh air and incorporate heat recovery. The other significant heat recovery system is installed at the kiln room where heat is captured in the colder months and redirected to a close-by variable air volume unit.
Solar Heating and Cooling
The 152 solar thermal collectors (29 ft2 each) on the south wing roof provide heat for a radiant floor heating system that extends throughout the facility. Additionally, this same solar system supplies more than 200°F water to a 50 ton absorption chiller.
A vertical, 15,000 gallon thermal storage tank is located outside and immediately adjacent to the main mechanical room, which houses the absorption chiller and two electric chillers. A gas boiler provides backup heating, and, if adequate solar energy is not available for cooling, the electric chillers are activated.
A closed solar loop is protected from stagnation by diverting flow from the solar loop to the same cooling tower used by the chillers. In the event of an unscheduled power failure during ideal collection times, a backup generator is engaged to continue the flow within the solar loop and cold municipal water is allowed to flow to a heat exchanger in the solar loop that cools the collectors. The municipal water is, in turn, routed into the rainwater harvesting tank to conserve the water.
Solar Water Heating
Domestic hot water is required for the lavatories, studio sinks and general cleaning. Seven collectors, coupled with a 400 gallon storage tank, provide the majority of the facility’s domestic hot water needs.
A 112 kW peak photovoltaic system consumes the majority of the remaining roof area. A total of 468, 245 W photovoltaic modules generate power that is being directed back into the utility’s grid. In approximately five more years the college will likely purchase the PV system, at which point the PV-produced electricity will be used to offset the building consumption in a net-metered approach.
Additionally, small PV systems power two emergency call stations, and a 1.6 kW dedicated array mounted on the roof of the Creative Arts Building powers a recirculation pump treating runoff water in the constructed wetland.
Whole-water cycle approaches are implemented to address the objective of improving water quality at the site while also serving to treat runoff from 3.45 acres of the campus immediately surrounding the building. Using native planting and a comprehensive storm water management approach that uses two sand filters, a constructed wetland pond and bioswales, more than 95% of the immediate site runoff, plus the runoff from the surrounding areas, is captured and treated. The net effect is that less nitrogen and total suspended solids leave the site now than before the project was constructed.
The vegetation in the bioswales and constructed wetland was specifically selected to capture nitrogen and filter the runoff water before it reaches the local mountain streams. The PV driven direct current pump circulates water throughout the wetland pond during the day to enhance water treatment. Post-development runoff from a two-year, 24 hour storm is less than predevelopment, and the implemented strategies are capable of treating a 10-year peak storm.
Low-flow fixtures reduce potable water demands 151,790 gallons per year below code requirements. The rainwater harvesting system, collecting from roof areas and using a 25,000 gallon underground tank and UV-treatment, saves more than 570,000 gallons of potable city water each year. The combination of low-flow fixtures and the rainwater harvesting system, used for toilet flushing and cooling tower makeup, reduces potable water demands by 74%.
Energy Design and Verification Process
The facility’s excellent, monitored energy consumption and below budget construction cost can be traced to extensive daylighting and whole-building energy simulations initiated at 50% through the schematic design phase and revisited throughout the remaining design phases. Because of differing lighting needs and occupant requirements, each major space was simulated to develop optimum daylighting solutions.
This analysis started in early schematic design as the design was being developed and spaces were modified to optimize daylighting contribution. An important component of this analysis was the team’s working closely with different studio instructors and determining their particular requirements — some driven by controlled, glare-free lighting levels and others by maintenance within their shops. The daylighting analysis conclusions at each design phase, consisting of contributions at multiple grid points within each space, served as hourly input into the whole building energy simulation.
Like the daylighting simulations, the energy simulations started at 50% schematic design and were updated throughout the design process. Given the college’s tight budget, the early whole-building analysis was vital in evaluating alternative approaches early in the design process.
A submetering system provides verification of the performance of each of the major energy-saving components. An extensive green monitoring system is additionally linked to a more detailed website accessible by the design team. Through real-time, daily and monthly subsystem monitoring, the design team was able to identify and correct during commissioning problematic control and mechanical components early in the first year of operation.
Haywood Community College faced numerous obstacles in its pursuit of a sustainable building that also preserved and enhanced the site. Despite the energy demands of the studios, the shade from surrounding trees and extended operating hours, the building meets energy reduction goals and improves the site’s water quality while preserving as many trees as possible.
Creative energy and environmental solutions, such as daylighting, passive heating and cooling, and solar thermal heating and cooling, were key to achieving the college’s goals. Whole-building energy simulations also played a critical role in taking full advantage of passive strategies and reducing energy use.
Ultimately, the college, students and the region benefit from the building’s reduced environmental impact and operating expenses. Students can pursue their artistic interests at community college prices, strengthening the region’s cultural and economic fabric.•