Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
You're seeing the difference in results from the warmup process that EnergyPlus performs. The difference in your window opening strategies are used over this warmup process, which is why the run period results that you're plotting have different initial conditions for zone air temperature.
If you search Unmet Hours for "energyplus warmup", you'll find many posts on the topic.
