CO2 concentration starts before people

[KasperS]

Hello

I have noticed in my calculations that the CO2 concentration starts to rise 30 min before the people arrive in the room. I spoke with a co-worker and she experienced the same in her models. Is there a reason for this and can it be eliminated?

From Kasper

[KasperS]

hey

I am using 2 min intervals, so that shouldnt be the problem.

From Kasper

[PCully]

Hi,

I haven't hear of this before, did some quick test sims with different time steps and reporting intervals but still didn't see this problem (I was using a 9-5 occupancy profile and Room CO2 didn't rise until 9 each time). You don't have your occupancy on a ramp profile or anything that might kick in before 9?

Only other area having an impact I can think of is MacroFlo, maybe try running with MacroFlo off, reduced number of rooms until you find the cause of the anomaly.

Phil

[KasperS]

Hey

I tried to test it if it was MacroFlo, but it did not help. I also tried to turn off HVAC.
I talked with another co-worker who did his master thesis using IES. He also said he encountered the problem, and IES gave him some long explanation, but he can't remember it anymore.