I am in my mid 30's, retired due to a disabilty, but learning silversmithing and falling in love with it. I am going to be moving into a new home here in about a month, and I really could use some advice. I would like to set up one of my rooms to be my workshop and I need to know the minimum reuirements for ventilation and air flow, etc. I will be using a natural gas system in a room around 20' x 15'. Thanks! Sandra B