How EnergyPlus determine the boundary condition before warmup convergence?
Hi all,
According to what I read from E+ engineering reference, the warmup process in E+ basically compares the four parameters: maximum zone air temperature, minimum zone air temperature, maximum heating load, and maximum cooling load for each individual thermal zone. So if the difference between days is less than the tolerance value, convergence is reached.
I understood that part, but still do not quite understand how the boundary conditions were chosen by E+ Since the warmup convergence itself has to go through the definition of boundary conditions such as indoor surface temperature.
Or can I just assume that:
In terms of specifying the indoor surface temperature directly as a boundary condition, EnergyPlus doesn’t typically require us to input this value explicitly. Instead, the indoor surface temperatures are calculated as part of the simulation process based on the interactions between the weather file, material properties, HVAC settings, and internal load. Since Honeybee usually assign a default value if we do not put anything.
Hopefully, somebody can clarify this. For example in Honeybee (using E+ engine), I only put weather file and material properties, and somehow E+ spits out values for indoor surface temperature, outdoor surface temperature, indoor air temperature, indoor operative temperature, etc. While in the heat transfer textbook, the heat balance equation might need the indoor surface temperature to actually calculate the outdoor surface temperature. So it baffles me. How can E+ spits out value with lots of unknown?
Thank you
Regards, Ricardo
