Utilizing feedback from consumers, we set out to build a much quieter, more efficient Forced-Air Heater. We developed our SilentDrive Technology to make that idea into the reality that is SilentDrive. A standard Torpedo heater uses the same air stream for both combustion and to blow hot air into the heated space. Our SilentDrive Technology separated those two processes while making each quieter and more efficient. The new design also drastically revised the fueling system, and now allows for variable BTU heat settings. This change has also gotten rid of all routine maintenance needed on a standard Forced-Air Heater. There are no filters to keep clean or rotor gaps to reset.