So I have been burning candles for a while now - always keeping an air flow to the outside in the room I was burning the candle which is my office. The door always closed as my office is also my private space and sanctuary.
Soot all over. I had to clean every wall, anything that had glass or plastic as the soot was layering over those surface more than others.
But the tragedy extended to my kitchen. I even had layers of soot inside my kitchen cabinets! How did it got there in the first place? Yes soot is particles held in smoke - but I never smoked my whole house! I wonder if there is something wrong with the wood wicks - or even an oil based wax perhaps?
I found the best place to burn is on a stove top with an exhaust over it. I've been able to keep my walls in pristine shape. Every week I clean the soot from under the exhaust.
It's wick quality. Newer candles have thinner wick and smoke a lot, if I'm in the room my nose gets full of black soot. I trim them down to literally 2mm and they smoke still.
Older candles that I bought year/two ago with wider wick never smoke and don't release soot
This happens mainly if you burn too much candles in a short amount of time, burn them for too long and don't trim the wicks each time you light them. I've had the same issues, soot EVERYWHERE even in my draws. I would suggest buying an air purifier which might help. Also, the candles are made of paraffin wax which is harmful if burned alot