I am currently trying to control an electric low temperature radiant in a building using bcvtb. Specifically, I am trying to implement a control algorithm (model predictive control) that controls the electric power generated by the radiant. Following the documentation from Energyplus (InputOutputReference and EngineeringReference), I assumed that the radiant power is linearly proportional to the difference between the set temperature and reference (zone) temperature. Hence, I measure the zone temperature at every time step and compute a set temperature, such that the difference between both multiplied with a constant factor gives me the desired power. However, this only works approximately. I never obtain the desired input exactly. In particular, the power flow seems to change also according to the outside and floor temperatures. Why is this so? Is there any other way to control the power flow through the radiant directly?
Thank you very much in advance, Alexandre
