Bear in mind that most of us doing "smoking" at home are hot-smoking. That is, cooking, with smoke included. You need a heat that will cook the fish/meat/whatever properly - and that is usually more than enough to get your chips or sawdust smoking nicely. Chicken breast fillet, for example, needs to reach an INTERNAL temp of 165 deg C to be properly cooked - and if you run a very low temp, it would take so long to reach that point that the meat would be dried out horribly, I reckon! If you're not getting smoke, I'd say you're simply not running it hot enough.
On the other hand, if you have a proper cold smoker, for curing and preserving meat and fish (eg, bacon, ham, kippers, etc) then your source of heat is under the chips, but the smoke is taken to a completely separate smoking chamber, and is already cool when it arrives there - so it's not cooking the meat, but smoke-curing it.