We disassembled our heater, and here you see 2 years' worth of sawdust. It's not as bad as I feared, but means that we need better dust collection, and also need to be more attentive to cleaning the heater. We're currently looking into a dust collector for the garage for the tools that have 4" ports, and will try to create an effective dust collection system for the Hegner, and for the sanders that are chucked into the SandFlee. Of course we always wear dust masks--would hate to think of that fine stuff coating my lungs. I can't imagine how anyone could work without the protection of the basic 3: dust mask, goggles, and hearing protection.