Abstract: A dual-rate fuel flow control system for the gaseous or liquid fuel supplied to the burner of a space heater, comprising a valve controllable to supply full fuel flow to the burner at the start of a heating cycle to deliver full heat to the heat exchanger chamber in which circulates the heat transfer fluid, and controllable to supply reduced fuel flow to the burner simultaneously with starting the circulating of the heat transfer fluid from the heat exchanger to the space to be heated.

Abstract: A dual-rate fuel flow control system for the gaseous or liquid fuel supplied to the burner of a space heater, comprising a valve controllable to supply full fuel flow to the burner at the start of a heating cycle to deliver full heat to the heat exchanger chamber in which circulates the heat transfer fluid, and controllable to supply reduced fuel flow to the burner simultaneously with starting the circulating of the heat transfer fluid from the heat exchanger to the space to be heated.

Abstract: A preheating device for the inlet manifold of an internal combustion engine, comprising at least one probe projecting into the exhaust manifold of the engine connected via a heat-conductive metallic rod or pipe to a second probe projecting into the inlet manifold, for transferring heat from the exhaust manifold to the fuel-air charge flowing through the inlet manifold. The probe disposed in the inlet manifold may be provided with an electrical heating element such as to preheat the interior of the inlet manifold prior to starting the engine, and providing heat to the fuel-air charge during cold starts of the engine.