Ventilation on GH / HB

Hi everyone,

I just realise something that I can’t explain about the assignment of the air supply on Honeybee.

In fact, there’s two tools which allows to assign the ventilation rate (per area or per person), the tool “HB_Set EnergyPlus Zone Loads” and the “HB_Set EnergyPlus Zone Schedule” tool. I first used the Loads tool to set my ventilation rate to 0.0003415 m3/s-m², after a simulation the annual total mechanical ventilation gain was 608.2 kWh. Then, I tried with the Schedule tool, setting the same value duplicated 8760 times to create an annual schedule as an input of the “HB_Set EnergyPlus Zone Schedule” tool. This time, after the simulation, I get -5811 kWh.

Do someone knows how to explain this ? How comes this difference ? Why the gain is negative in the second simulation while it’s positive in the first one ?

Any thoughts would be helpful, thanks !

First simulation (with Loads tool) :

Second simulation (with Schedule tool) :

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