RADIANT HEATING SYSTEM RESET CONTROL

摘要

A control unit and a related method of operation for controlling the temperature of the water circulated in the radiant loop of a hydronic heating system. The control unit includes temperature setting dials that can be used to adjusts the reset curve used to determine the desired secondary, radiant loop water temperature. The control unit generates a linear reset curve between two setpoints such that the control unit can calculate a desired secondary loop water temperature based on the reset curve and the present outdoor air temperature. The control unit monitors the temperature of the water returning to the boiler from both the primary loop and the secondary, radiant loop. The control unit monitors the return water temperature over a first interval and, based on the rate of change in the return water temperature, calculates a predicted return water temperature at a second interval in the future. If the predicted return water temperature is lower than the user-selected minimum return water temperature, the control unit operates the modulating valve to reduce the amount of heated water flowing to the secondary, radiant loop.