I brew in my basement, but after several all grain batches I'm worried about my HVAC ductwork. The cold air return duct over my brewing spot has far more visible handprints than anywhere else on the ductwork. I have not handled the ducts, and presume the condensation from brewing is getting to be more than the galvanizing can take. I don't want to rust those, so I'll be moving to the back of the basement by the door, where no ductwork is exposed. I also plan to open the door and use a fan for ventilation during the boil. A range hood would be really nice, but will have to be a bit further down the line.
I am using natural gas &/or heatsticks. I don't own any propane stuff.