The Fauquier High School "Cube" Building was equipped with inefficient unit ventilators featuring hot water heating coils and direct expansion cooling coils. B&N, working with ABM Infrastructure Solutions, transformed the schools’ energy efficiency by employing a variable refrigerant flow (VRF) heat recovery system. This solution revolutionized the building's HVAC system, designing custom unit ventilator cabinets retrofitted with Mitsubishi VRF fan coil components and total-enthalpy energy recovery wheels.
VRF heat recovery systems, like the one designed for the building's HVAC system, involve a network of indoor evaporator units linked to one or more variable speed condensing units. This advanced technology ensures that the compressor only consumes the energy required to match the building's load, due to the variable speed drives integrated into the VRF compressors. Another notable feature of these systems is their heat recovery capability. When zoned appropriately, the VRF systems operate close to a net-zero system during winter months. The design repurposes the heat from the core spaces of the building that require cooling, transferring it to perimeter spaces that need heating, through a series of valves called "heat recovery boxes". This results in a significant increase in energy efficiency and cost savings.
Improving air quality was another critical aspect of this retrofit project. B&N utilized the Indoor Air Quality (IAQ) Method outlined by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) 62.1. By incorporating cutting-edge bipolar ionization devices into the new HVAC equipment, B&N was able to reduce the code-required outside air intake by 50%. This innovative approach not only improved the overall air quality in the building but further enhanced the system's energy efficiency.
This ambitious project demonstrates B&N's dedication to providing clients with cost-effective, energy-efficient, and high-performing solutions. The Fauquier High School "Cube" Building now boasts a state-of-the-art VRF heat recovery system, significantly reducing energy consumption while enhancing indoor air quality. This transformation sets a benchmark for future school building retrofits, reflecting B&N's drive to create more sustainable and efficient educational environments.