Comment by marcosdumay

6 hours ago

https://gml.noaa.gov/ccgg/trends/

Extending the current exponential for 20 years, we get into the 500ppm region.

I don't think that's enough to need scrubbers.

Indoor is always higher ppm (how much depends on many parameters) without proper ventilation. „Proper“ should include a „Heat exchanger“ thus you don’t need to reheat fresh air.

  • Still, it will add some 80ppm over the amount you have today. There's a huge amount of disagreement over how much CO2 is harmful, but it tends to happen over numbers way above 800ppm.

    If your room has 2 times the open air concentration, and you are concerned if it's 2.0 times or 2.2 times, you should already be dealing with the problem.

    • It's not way above, it's around 700+.

      So at 500 external you'd pretty much need continuous ERV but not necessarily scrubbers just yet.