I have been burning a bunch of 7018 and a little 6011 trying to practice. I have had lots of ventilation for the fumes. The thing is that the weather is starting to cool off and I wanted to know how much ventilation that I need to have. I'd like to go inside and close the shop door a bit to stay a little warmer. I will say that the cold encourages me to weld almost constantly! My little inverter welder doesn't mind because I stay at the 100% duty cycle amperage or below.