Iterative daylighting calculations EnergyPlus
Is it possible to calculate the indoor daylighting illuminance during a timestep for two different situations: once with the shading (partly) closed and once with the shading open? For several timesteps, I need both values for evaluation in a Python plugin code, so ideally, I can specify in the code whether the second iteration of daylighting calculations should run and with which shading occlusion rate. At first glance, I didn’t find an option in EnergyPlus to iteratively calculate the indoor daylighting illuminance, although this seems the most straightforward approach.
Other options I’ve considered are: (i) Estimating the impact of the solar shading on the illuminance by integrating a (simplified) daylighting calculation into the Python script, but this may result in inconsistencies in the indoor illuminance values, or (ii) Starting a separate simulation for that timestep that calculates these values with the correct shading occlusion rate, but this would increase simulation time (if it’s even possible).
Does anyone have any ideas on how to address this issue? Thanks in advance!
Hello! Did you find an answer? I’m trying to control the slat angle of a blind. I defined the shadow‐calculation object on each timestep using the Python API, but I’ve noticed that changes to the slat angle take effect with about a three‐timestep delay.
Hi I've decided to go further with option (ii): starting a separate simulation in python plugin on the moment I need these iterative calculations and run the simulation only for that day. For my simulation goal, this approach does what needed: I can retract the illuminance values for various shading conditions to use them as input for another decision-making process. Best of luck!
Hello, Actually i have another goal for this simualtion is to use Python API to modify the slat angles at each time step but i have a delay in the calculation of illuminance, just for reason of test i did a code to alternate between 60 degree and 180 degree and i find that the illiumiance values when i apply the action 60 comes with the slat angle 180 degree (because i retreive the value of the slat and and the corresponding illuminance) so its a delay of one time step i used this callback to send an action callback_begin_zone_timestep_before_init_heat_balance and i literally tried all of them