Florida Middle School Upgrades HVAC System and Saves
Indoor air quality issues persist in existing public schools across the U.S., so retrofits that are both energy-efficient and cost-effective are in high demand.
K-12 students face many daily challenges in school, but having to study and learn in an uncomfortable climate should not be one of them. However, while advanced building systems and technologies are available to eliminate this issue, many school districts struggle to secure funding to properly maintain and update school infrastructure.
Best Environment to Learn
Students learn more in a comfortable enviroment
A recent study from the National Center for Education Statistics found nearly half of public schools in the U.S. have reported issues with indoor air quality. Students, teachers, and administrators work and learn more productively when their physical environments are properly controlled and comfortable.
To address aging and outdated building systems and to improve the learning environment for its own students and faculty, Hernando County School District in Brookville, Florida recently engaged Daikin Applied for an HVAC system overhaul at West Hernando Middle School. Erik Van de Boogaard, Hernando Country School District’s facility operations director and the district set out to secure funding for critical updates to the middle school campus’s building systems.
Selecting a contractor and HVAC technology
West Hernando Middle School students and faculty were feeling the effects of the campus’s outdated HVAC technology and the need to replace equipment at the end of its lifecycle was imminent. “We really wanted to hear from the HVAC industry about systems that will be the best fit for this particular campus. Daikin recommended a split-system dedicated outdoor air system (DOAS) consisting of their rooftop condensing units and indoor air handling units, along with their variable refrigerant volume (VRV) equipment and technology, which we felt was the most innovative, cost effective, and practical solution. That’s why we chose them.” said Van de Boogaard.
In an effort to streamline the construction timeline and minimize costs for the school district, Daikin acted as general contractor on this project. It oversaw the design and replacement of the existing water source heat pump system that currently resides above ceilings in each building. Additionally, working closely with a local engineering firm and builder, Daikin helped to upgrade building insulation and replace the electrical system with a modern,energy efficient option. “The building structures do not accommodate traditional HVAC systems and we didn’t want to just replace air handling units,” said Van de Boogaard. “The new HVAC equipment and electrical system will work together to better manage building comfort, humidity, and temperature, keeping energy costs down.”
The project installed a split-system dedicated out-door air system (DOAS) consisting of rooftop condensing units and indoor air handling units, along with variable refrigerant volume (VRV) equipment and technology.
Efficiency via Flexibility
The project spans seven buildings, each with a different footprint. Incorporating split-system DOAS equipment for each building retrofit provides conditioned fresh outdoor air to the indoor air space at 70°F and 50% relative humidity. The DOAS equipment is essential to creating an enhanced, comfortable and productive learning environment, as well as meeting ASHRAE’s 62.1 standard for building and ventilation requirements.
The VRV equipment is ideal for the retrofit because it meets the district’s need for a highly energy efficient solution, and the flexible refrigerant-based system can accommodate various building designs.
VRV heat recovery technology has been selected for the majority of the project because it allows for independent and simultaneous zone-based heating and cooling.
This means that a teacher who has a room with southern exposure can have her room set for cooling while another teacher with a northern exposure could havehis room set to heating—all simultaneously, from the same system.
A Three Phases Project
The middle school project was completed in three phases and timing for each was critical. Construction on each phase had to start and be finished during the summer months, while students and teachers were on summer break. In the summer of 2015, phase one kicked off with a system overhaul at building seven, consisting of 40 tons of added VRV units combined with a split-system DOAS.
“The capabilities of HVAC technology have evolved significantly since the last time this campus system was replaced,” said Van de Boogaard. “The ability to remotely access and control the system introduces a user-friendly component that my team will find value in. The controller dashboard will also make training my staff easier. The intuitive features of this system are very beneficial.”
Phase Two kicked off in May 2016 and consisted of updates at two buildings primarily made up of classrooms.For this phase of the project, the school district again opted to install the DOAS equipment for improved ventilation, as well as a VRV heat recovery system because it enables zone-based heating and cooling that the teachers can manage. The DOAS and VRV equipment were also used in the project’s final phase, which took place in the summer of 2017.
Energy monitors recorded 40% savings. Energy savings measurements were compiled one month before the old equipment was removed and one month after the new equipment was installed. The middle school realized 40 percent energy savings that it attributes to DOAS and VRV, overall. These results are assets that Van de Boogaard and school administrators can communicate to the district leadership and school board, to clearly demonstrate the ROI of this important and partnered investment.