A: First off, the cubic volume of your storage area is 392 cubic feet. Each individual canister is designed to cover a maximum of 3 cubic feet. The best option would be to use the smaller canister in each individual box that you are storing in the unit. If you are wanting to use silica gel to cover the entire volume of the storage unit you would need 5,227 grams(or 11.52 lbs), so I would suggest going with a higher volume canister to get the appropriate coverage for your area.
A: Yes. This product is suggested for use in containers up to 3 cubic feet.