Code Readiness Case Study: Energy Recovery Dedicated Outdoor Air System and Heat Recovery VRF Retrofit: Office Building in Sacramento, CA

The Sacramento Case Study is one of eight buildings evaluated under a Code Readiness field monitoring research effort to better understand real-world performance of dedicated outdoor air systems (DOAS) in California. The Sacramento site was renovated in 2019 with a partially decoupled HVAC system using a DOAS unit with an energy recovery ventilator (ERV) and a multi-zone VRF system with heat recovery for space heating and cooling. This case study will share site HVAC configuration attributes and energy efficiency observations including heat recovery effectiveness, peak demand reduction, and VRF heating and cooling system efficiency. This case study will highlight the effectiveness of DOAS and VRF energy efficiency components and identify code and market mechanisms to support adoption of high-efficiency DOAS and VRF system. In contrast to mixed air systems, DOAS HVAC configurations achieve efficiency by independently optimizing the ventilation and/or conditioning system. Prior studies from other parts of the US indicate that using a dedicated ventilation system that heats, cools, and dehumidifies outdoor ventilation air can significantly reduce annual energy consumption, and both winter and summer peak loads. However, few studies have assessed the performance of DOAS systems in California’s unique climate or evaluated variation in performance for different DOAS system attributes, technologies, and strategies.