I want to construct a CAV system that use the indoor air (return air) temperature to control the chilled water flow through the main cooling coil. However, the cooling coil becomes malfunction (water mass flow =0) after i used the return air node as the sensor node in Controller:WaterCoil. And i found that the coil is working fine if the sensor node is the supply air temperature. I want to ask about how i can construct the CAV system using the return air temperature as the set point. Thank you.