New Foundation Headquarters in Houston Utilizes Renewable Geothermal and Solar Energy
The Ella B. Scarborough Community Resource Center is a new, state-of-the-art health and human services facility serving Mecklenburg County, North Carolina. CMTA provided energy modeling and analysis for this project, utilizing a combination of software and DOE database reference to develop real-world data for the facility. This comprehensive approach resulted in over $92,000 in yearly utility incentives. As part of this effort, CMTA led the sustainability charettes at each stage. While not pursuing LEED certification, the facility was designed to LEED checklist goals with an aggressive targeted EUI. Additionally, all systems were designed to drastically exceed code minimum requirements and optimized to perform Zero Energy.
The project team studied all features of the building envelope, including walls, windows, and roof systems, as well as the building’s orientation. Modeling was used to demonstrate the benefits of a “tight building” to the owner and design team. Due to the available land plot, the building’s predetermined orientation was less than ideal, as it followed a long east/west arrangement. As a result, the team focused heavily on active and passive shading devices, as well as interior program organization to minimize glare. Additionally, glazing selections were optimized to balance energy consumption with daylighting of the learning environments.
The design features three dedicated outside air units, each equipped with a total integral energy recovery wheel for heat recovery. These units deliver filtered and pre-conditioned air throughout the building and operate decoupled from the geothermal systems. Outside air is delivered directly from the dedicated outside air unit to individual spaces to maximize effectiveness. The building also incorporates demand control ventilation strategies and dehumidification mode operations, which regulate air delivery throughout the building based on carbon dioxide and humidity levels. These features ensure efficient and regulated air circulation throughout the building.
A detailed life cycle analysis was performed to compare three system options for the project, including first costs, energy costs and maintenance costs. Based on the results, the owner selected all-electric, ground-source geothermal heat pump units to both heat and cool spaces throughout the building. These high-efficiency units contain ECM fan motors and two-stage compressors. The geothermal wellfield consists of a series of manifolded vertical bores piped directly to the building circulating loop. Along with 84, 500-foot-deep geothermal wells, the building also boasts a 356.4 kW photovoltaic system.