Can someone let me in on this?

I wasn’t inspecting the HVAC, it was a mould inspection but can’t help but wonder why this is. I am waiting for lab results, one year old house with some “black stuff” on basement studding. Unexplained breathing problems, rashes etc. since they moved in. My question is why is the fresh air blocked off? Owner has no idea.Am I just missing something here?[ATTACH]


Some people decide that the cold air falling from the fresh air make up is a problem.

What they often don’t realize is that the the combustion air will come from outside anyway through every crack in the building envelope.

Blocking combustion air is a good way to starve the furnace for air and promote backdrafting and CO. :shock:

If I hadn’t been through this already I would guess that the said " why is there a vent from the outside to the furnace???" That is what I said the first time…