Since people and ventilation rate are already recorded entered in the usage profiles for the thermal simulation, the CO2 content of the indoor air can be calculated without any further input.
The only sink is the ventilation. Outdoor air is assumed to be a constant 415ppm CO2 (about average 2020, increasing by over 2ppm per year). Indoor plants are negligible , - they absorb small amounts of CO2 during the day and release it at night, only during growth the uptake is predominant.
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