The Therma-Fuser™ thermally-actuated VAV diffusers are simple to install, require no maintenance, come with a 10-year warranty, and offer the lowest cost per zone of control. Each Therma-Fuser Stand-Alone diffuser is an independent zone of VAV control with built-in thermostat and modulating damper. The dampers are mechanically positioned by thermostat/actuators and have no complicated electronics, no wiring or pneumatics.