I cold smoke all kinds of products to sell at the local farmer’s markets. Altho I use the Masterbuilt setup I’ve seen other people make their own with a 3" dryer vent hose.
The only trick is to keep your smoke generating source away from your smoker unit as all smoke will contain some heat. The father away the better for your product. Also make sure you’re smoker unit isn’t parked in a sunny spot as this will also increase the temperature inside the unit itself. I have to use a sheet of plywood on the side of mine in the early mornings to keep the sun from hitting it.