I purschased a turbine spray system from rockler and it works great. Now I have a small 8'x6' closed off when spraying, but it is way to tight for being able to walk around a peice. In the new shop which is 30'wx60'lx12'h, so I want to make a seprate area just for that. What size should it be? I was thinking of 15'x15'x 10'h. What size would you make if you had the given size area to work with?