In addition to Mr. T's post, I'll chime in with my .02
I use a FEC100 at my restaurant, which is used for both hot smoke for meats & cold smoking. The primary cold smoke items are either trout or salmon. Both are brined prior to smoking.
The actual cold smoking process utilizes a perforated cylinder, found
HEREThe brined fish fillets are placed on the racks and the pellet tube is filled with pellets, ignited and allowed to rest on the bottom of the FEC 100, producing smoke for x number of hours. Sides of salmon typically require about 4 hrs, trout about 1.5 hrs. The FEC is never turned on...it simply becomes the vehicle holding the smoke in the chamber while the fish gathers smoke.
I've tried this method with fresh Mozzarella and it does a admiral job as well.
Given a hot day and ambient outside temps in excess of 80 degrees, I'll fill a 6" deep hotel pan with ice cubes and place it between the tube smoker and the fish/cheese above to keep the internal smoker temp below 90 degrees.
This method is easily converted to a smaller smoker such as yours.