Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
OpenStudio and EnergyPlus can controls lights based on daylight comfort by using the Daylighting Control object. They don't however offer a way to factor in zone temperature or to change the Daylighting Control object characteristics seasonally. If you want to do either of those you would have to use EMS (Energy Management System) objects in a measure. You could also manually adjust the lighting schedule to mimic this by lowering the peak levels lower in summer vs. winter.
If your goal is just to avoid any excessive electric lighting, could you just set the Daylighting Control characteristics at the lowest level that provides enough light all year round, or do you want to be more aggressive in summer than in winter with target lighting level?
The thing to be careful about is that OpenStudio and EnergyPlus do not run an electric lighting simulation to calculate lighting levels. If you undersize your HVAC system you will see unmet hours. There isn't any obvious indication of an under lit building. You need to look at the efficacy of your lighting technology and make sure that the installed and scheduled lighting power (installed watts * fractional schedule value at timestep) is enough to light your zone.
| | 2 | No.2 Revision |
OpenStudio and EnergyPlus can controls lights based on daylight comfort by using the Daylighting Control object. They don't however offer a way to factor in zone or outdoor temperature or to change the Daylighting Control object characteristics seasonally. If you want to do either of those you would have to use EMS (Energy Management System) objects in a measure. You could also manually adjust the lighting schedule to mimic this by lowering the peak levels lower in summer vs. winter.
If your goal is just to avoid any excessive electric lighting, could you just set the Daylighting Control characteristics at the lowest level that provides enough light all year round, or do you want to be more aggressive in summer than in winter with target lighting level?
The thing to be careful about is that OpenStudio and EnergyPlus do not run an electric lighting simulation to calculate lighting levels. If you undersize your HVAC system you will see unmet hours. There isn't any obvious indication of an under lit building. You need to look at the efficacy of your lighting technology and make sure that the installed and scheduled lighting power (installed watts * fractional schedule value at timestep) is enough to light your zone.
