.Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeating .Buildings.Applications.DataCenters.ChillerCooled.Equipment.CoolingCoilHumidifyingHeatingThis model can represent a typical air handler with a cooling coil, a variable-speed fan, a humidifier and an electric reheater. The heating coil is not included in this model.
The water-side valve can be manipulated to control the outlet temperature on air side, as shown in Buildings.Applications.DataCenters.AHUs.Example.AirHandlingUnitControl.
It's usually undesired to control the outlet air temperature by simultenanously manipulating the water-valve and reheater, because energy waste could happen in this case. For example, under the part-load condition, the water valve might be in its maximum position with the reheater turning on to maintain the outlet air temperature. To avoid that water-valve and reheater control the outlet temperature at the same time, a buit-in reheater on/off controller is implemented. The detailed control logic about the reheater on/off control is shown in Buildings.Applications.DataCenters.ChillerCooled.Controls.Reheat.
The humidfier is an adiabatic spray air washer with a prescribed outlet water vapor mass fraction
in kg/kg total air. During the humidification, the enthalpy remains constant.
Details can be found in
Buildings.Fluid.Humidifiers.SprayAirWasher_X. The humidifer can be turned off
when the prescribed mass fraction
is smaller than the current state at the outlet, for example, XSet=0.