There are a couple of ways you can cold smoke with the Bradley. One way is to build or purchase a cold smoking adapter. Another way is to leave the generator attached and add ice to the cabinet. It is important to keep the cabinet temperature below 90°F. I personally like to keep the cabinet to 70°F, when I can. A digital probe thermometer is important if you want to correctly monitor the cabinet temperatures.
Making your own can be very simple or you can make a more "advanced" setup. The picture below shows a cold smoke setup made from plywood. Others have made them from metal mailboxes to a variety of objects.
I generally make mine out of a cardboard box. Hopefully the below link works. If not I can post the instructions, or you can search this forum for the various types of cold smoke setups members have come up with. Cardbaord Cold Smoke Setup
If you don't want to or don't have the time to make or purchase a cold smoke setup, you can use ice to keep the temperature down. Using blocks of ice works better than ice cubes. You can make blocks of ice by freezing water in used 1 quart milk cartons, or freezing water in food storage containers works well. You can also use reusable freezer packs, but place them in sealable bags to keep them clean from smoke. The cold ice will impede the flow of smoke so keep your vent wide open. Even with the cold smoke setup, keep your vent wide open.
The ice may not be enough to keep the temperature below 90°F, so you may either have to wedge the door open a little, such as sticking a pencil in the door to prevent it from closing completely, or occasionally opening the door to let some of the heat to escape. Of coarse smoke will also escape, but there will be plenty of smoke to flavor you salmon.
Some other tips:
•Make sure the area you setup the generator on is level.
•Smoke during the cooler parts of the day, early morning, late evening or night time.
•Keep the cabinet in the shade, out of sunlight.
•During warmer days, ice can be placed inside the cabinet to help keep the temperature down.
•Unplug the heating element.