Sorry guys.....it has been a long while since I have been on HBT. I am opening up another private practice PT clinic and have been elbows deep in that project. I haven't made any progress on the brewery and I haven't brewed at all in months.
To answer your questions about my system. I am taking the necessary precautions to prevent any rouge yeast or baterial from contaminating my wort after the boil. I typically mill and bag my grains the night before my brewing sessions. As indicated, the grain drops down a chute and into a bucket in a completely closed and sealed compartment build within the cabinet of the milling station. To this point, I have experience minimal dust from the top end of the mill. I keep a shop vac in an adjacent utility room and vacuum out the cabinet and wipe down the hopper and cabinet top after each use.
I have designed my system such that after the boil, the wort is pumped through a plate chiller and directly into carboys already sitting down inside of my fermentation chambers. My fermentation chambers have 2 lids each, one insulated lid that creates an air tight seal and a decorative tiled lid over that. My chambers are never left open or exposed to any particulate that could be floating in the air. The only time they are opened is to insert or remove carboys. I have been milling grains down there and using my chambers for quite some time without incident. Once I'm doing the entire brewing process down there, I honestly feel that with the precautions that I have taken, the risk of contamination will be minimal. Thoughts?