For most cold smoking, you do not need heat....
Cold smoking at 52-71° F (12-22° C), from 1-14 days, applying thin smoke with occasional breaks in between, is one of the oldest preservation methods. We cannot produce cold smoke if the outside temperature is 90° F (32° C), unless we can cool it down, which is what some industrial smokers do. Cold smoking is a drying process whose purpose is to remove moisture thus preserving a product.
You will find that different sources provide different temperatures for cold smoking. In European countries where most of the cold smoking is done, the upper temperature is accepted as 86° F (30° C). The majority of Russian, Polish and German meat technology books call for 71° F (22° C), some books ask for 77° F (25° C). Fish starts to cook at 85° F (29.4° C) and if you want to make delicious cold smoked salmon that is smoked for a long time, obviously you can not exceed 86° F (30° C). Cold smoking assures us of total smoke penetration inside of the meat. The loss of moisture also is uniform in all areas and the total weight loss falls within 5-20% depending largely on the smoking time. Cold smoking is not a continuous process, it is stopped (no smoke) a few times to allow fresh air into the smoker.