Code Readiness Report: Evaluation of Dedicated Outdoor Air System and Variable Refrigerant Flow System Controls at Nonresidential Field Sites
Project Number ET18PGE1902-5 Organization PG&E End-use HVAC Sector Commercial Project Year(s) 2018 - 2023This research was performed to help those involved with the development and implementation of California’s Title 24, Part 6, Building Energy Efficiency Standards (“Title 24”), better understand the real-world performance of dedicated outdoor air systems (DOAS) and variable refrigerant flow (VRF) system controls. Past research studies have demonstrated that decoupled HVAC systems, such as DOAS and VRF, can achieve high energy savings with high-efficiency components. However, few field demonstration research projects of DOAS and VRF controls have been performed in California. This Code Readiness research project collected field data at five California commercial buildings for 12-18 months and evaluated the following seven different control strategies on an energy, peak electric demand, and implementation experience basis:
- DOAS heat recovery bypass control
- DOAS zone demand control ventilation (DCV)
- DX-DOAS supply air temperature control
- VRF zone temperature control
- VRF afternoon cooling demand management
- VRF morning warm-up demand management
- VRF fan coil deadband fan speed control
This report summarizes the energy consumption, peak electric demand, and implementation impacts of advanced controls for decoupled DOAS and VRF systems. In addition, this report evaluates each control’s potential for incorporation into Title 24, Part 6 (Title 24) and presents code language recommendations.
Keyword Search:
Dedicated Outdoor Air System, Decoupled HVAC, DOAS, Variable Refrigerant Flow, VRF, Ventilation, Heat Recovery Ventilation, Energy Recovery Ventilation, HRV, ERV, building electrification, energy efficiency, retrofit, office, non-residential, commercial, demand control ventilation, peak demand reduction, heat pumps, building controls, economizing, controls, heat recovery bypass control, supply air temperature control, zone temperature control, afternoon cooling demand management, morning warm-up demand management, VRF fan coil deadband fan speed control