Frost protection – VAV type
Plant mode 8 (Room low temperature protection) places VAV boxes in control mode and heat sources at 100%, but it is not used by any AFs. If frost protection is required, a CFC chart specific to the project must be created (with a room temperature low and high limit) to command and release the device operating modes.
This feature does not rely on an outdoor air temperature signal. It uses temperature sensing in the room.