.Buildings.Controls.OBC.RadiantSystems.Cooling.HighMassSupplyTemperature_TSurRelHum .Buildings.Controls.OBC.RadiantSystems.Cooling.HighMassSupplyTemperature_TSurRelHumController for a radiant cooling system.
The controller tracks the surface temperature set point
TSurSet by adjusting the supply water temperature set
point TSupSet based on the output signal
y of the proportional controller. Both, the surface
temperature set point TSurSet and the resulting supply
water temperature set point TSupSet are limited by the
dew point temperature that is calculated based on the inputs
TRoo and phiRoo. The pump is either off
or operates at full speed, in which case yPum = 1. The
pump control is based on a hysteresis that switches the pump on
when the output of the proportional controller y
exceeds 0.2, and the pump is commanded off when the output
falls below 0.1. See figure below for the control
charts.
ASHRAE Standard 55-2004 recommends that the surface temperature of a radiant floor is above 18°C to avoid discomfort for spaces in which people wear typical footwear.
For systems with high thermal mass, this controller should be left configured as a P-controller, which is the default setting. PI-controller likely saturate due to the slow system response.