Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
DA, forget about all those issues and verify if the VRF system can maintain the zone loads mid- to late-day. Look directly to the control zone. What is the terminal unit and condenser PLR on the design days? What is the VRF sizing results compared to the zsz results? Setpoints don't typically ramp up, they set back or set up, it's the system that responds to this step function gradually. VRF systems can't respond to load in a zone when other zones are in the opposite mode (e.g., cooling vs heating), unless heat recovery is used. Even then there are limitations in performance. Focus on the design days to see what the limitations are in each season.
