Are building smoke generators different to locomotive ones?

Building smoke generators are different from locomotive ones in two main areas, size and voltage.

Smoke generators that are designed specifically to operate from within a locomotive's bodyshell have a distinct disadvantage: they have to fit into an incredibly small space. This means that they can't be very big and for that reason, although they are good, they are not quite as good as larger ones that are designed for use in model buildings.

Another characteristic of a locomotive's smoke generator is that it has to operate off the same voltage as the locomotive. This by default means a maximum of 12-14V, and that's for generators designed to produce fake steam at a model's top speed. A more common set up would be for a generator to be designed to produce smoke at a much more relaxed 4-7 volts so the locomotive is capable of producing smoke as it is starting off.

Building smoke generators are designed to work from a stable 16v auxiliary supply making them more powerful and more reliable at producing smoke.