Case Study: Consulting Engineering
CMTA built on years of sustainable design to take the challenge of reducing energy consumption for the new Bluestone Elementary School for Harrisonburg City Public Schools in Harrisonburg, Virginia. Thanks to our expert consulting and design team, CMTA was able to exceed the client’s energy efficiency goals, while maintaining the project budget.
CMTA is passionate about how a building and its systems can be utilized as a teaching tool.
When we began working with Harrisonburg City Public Schools, the project team was requested to meet a budget that typically provides an average school for the district; however, the design team challenged the client to believe more was possible. By attacking energy use targets, discussing several HVAC and lighting options, and collaborating with the owner, Harrisonburg City Public Schools was able to drastically reduce their energy consumption without adversely affecting the budget and providing a less complex HVAC system(s) as provided in the previous schools.
To push this project to the next level, we worked with the school district in researching the available HVAC and lighting systems, providing options which addressed the owner’s maintenance concerns while reducing their average energy consumption by sixty percent. During initial HVAC discussions, several maintenance concerns were mentioned, including an issue at the recently built high school which included a conventional boiler/chiller/VAV system in which the maintenance department could not get replacement parts for the newer equipment. CMTA’s solution, based on past success and Data-Driven Design, led the owner to the decision of using a geothermal heat pump system which was much easier to maintain while consuming less energy than their existing schools. Harrisonburg City Public Schools requested philosophy was to “keep it simple.”
One challenge that our team had to overcome was the philosophy of doing the same thing as included in the previous designs. The design team proposed several approaches to the project, including site layout, building design, and energy modeling; the final approach provided an energy efficient solution while providing a school which met owner’s educational goals. CMTA was able to truly partner with the architect and owner, designing a school with excellent learning environment that would drastically reduce the district’s typical energy consumption.
Decorative lighting is typically not affordable or efficient. In order to avoid breaking the budget or increasing energy usage the design team searched for ways in each space to use inexpensive LED lighting fixtures for maximum effect. This involved detailed discussions and close coordination with the architectural team to ensure a cohesive design. Decorative fixtures were provided in high impact areas while maintaining simplicity and clean lines in all other spaces. A granular, recursive approach to lighting simulation ensured reduced fixture counts as well as prevented over-lit spaces. This helped allow the project to bid under budget while achieving a Lighting Power Density (LPD) of 0.43W/sf or approximately three times better than code minimum.
Sustainable 21st century schools are designed to provide a high-level learning environment including connections to the outdoors. These schools include many features including break-out learning spaces, large windows providing great views, higher ceilings and specialized ceiling systems. The CMTA design team takes great care in coordinating with the architect to provide MEP systems which integrate into the architectural design features and better the learning environment. Our MEP systems reduce noise, improve the air quality and prioritize natural lighting.
Sustainable design is effective when the design team considers all aspects of maintenance. There are several components in the building which require maintenance, including lighting, low voltage systems, HVAC components, and system controls. CMTA’s designs minimizes components that require maintenance by eliminating complicated components or components that usually fail. For example, controls are kept simple, eliminating all but simple lighting controls and minimizing or deleting high maintenance control devices like wall mounted CO2 sensors or building pressure sensors. Maintenance needs to consider even smaller HVAC devices like electrical unit heaters. These devices are inefficient and are likely to fail, thus the use of electric unit heaters are eliminated or minimized.
CMTA was able to push the envelope on the client’s goals to help them achieve a Zero Energy ready school while achieving LEED Gold certification without sacrificing any of the school district’s learning goals. The elementary school is located on a 10.8 acre post-agricultural site with varied topography and sweeping views of the mountains. The three-story school design allowed for more site area dedicated to student use creating a communal, active, bio-diverse habitat. The design allowed great views to the environment without increasing the glass percentage over 30 percent. This efficient glass to wall ratio provided efficient envelope design.
Bluestone Elementary will be one of Virginia’s great performing schools with an anticipated Energy Use Index of less than 20, and we were able to achieve these results without additional first costs. The facility maintains comfort and air quality conditions, which improves learning, while maintaining the students connection with the environment.
This project has further solidified our belief that all schools nationwide can achieve outstanding learning environments while pursuing low energy goals, both without increasing the budget or requiring extraordinary maintenance efforts on behalf of the staff.
