A combustion air proving (CAP) system for a burner assembly having a burner for providing heated air to a location, a controller, and a back plate, where outside air is fed to the burner via a conduit. The CAP system is connected to an inlet of the system. An outlet of the system is connected to the burner via the back plate. A damper within the system is translatable between open and closed positions for allowing and blocking air flow, respectively. A sensor measures an air flow parameter of air flow to the burner. The sensor communicates with the controller, which shuts down the burner if the parameter measured by the sensor meets a predetermined threshold value. An assembly installer may test for proper sensor and controller functions by translating the damper to the closed position and blocking outside air flow.

Exemplary embodiments of a system and method for bimodal air control in a kettle-style grill are configured to be detachably mounted to the exterior of a kettle-styled grill such as, but not limited to, a Weber charcoal grill. When mounted to the kettle-styled grill, a plenum-like component directs air flows to the interior of the grill's kettle via the kettle's lower body damper holes. A manually adjustable intake damper in the plenum component allows, restricts, or prevents a drawn ambient air flow into the plenum component. Separately, a forced air flow generated by a fan may also be provided into the plenum component. Adjustment of the intake damper may also adjust damper blades inside the grill's kettle. Ash that falls out of the kettle's damper holes falls through the plenum component and is captured in an ash receptacle that is removably mounted to the plenum component.

The object of the present invention is a ventilated hob (400) comprising a motor-driven fan (V) adapted to provide high pressure air to two or more burners (BRNi) thereof, each of said two or more burners (BRNi) at least comprising means (VG, 211; 211.a, 211.b) for supplying and regulating the flow of fuel gas (Q.sub.GAS) in input into each of said two or more burners (BRNi), means (VP; 101; UG) for supplying the flow of combustion air (Q.sub.AIR) in input into each of said two or more burners (BRNi), able to mix with said fuel gas, shut-off valves of the flow of said combustion air, an electronic unit (.sub.CMD) for controlling said air flow (Q.sub.AIR). The air flow (Q.sub.AIR) varies as a function of said flow of fuel gas (Q.sub.GAS) in input into each of said two or more burners (BRNi) so as to ensure a gas-air mixture with a stoichiometric or substantially stoichiometric ratio without the need of input of secondary air from the outside, said variation of air flow (Q.sub.AIR) being obtained by varying the pressure of the combustion air in said sealed circuit (CA1, 405, 407) inside said hob (400). Said pressure is intermediate to the single pressures that each active burner (BRNi) should have.

A combustion air proving (CAP) system for a burner assembly having a burner for providing heated air to a location, a controller, and a back plate, where outside air is fed to the burner via a conduit. The CAP system is connected to an inlet of the system. An outlet of the system is connected to the burner via the back plate. A damper within the system is translatable between open and closed positions for allowing and blocking air flow, respectively. A sensor measures an air flow parameter of air flow to the burner. The sensor communicates with the controller, which shuts down the burner if the parameter measured by the sensor meets a predetermined threshold value. An assembly installer may test for proper sensor and controller functions by translating the damper to the closed position and blocking outside air flow.

Impeller for a radial fan, the impeller comprising a front side, a rear side and a peripheral edge, a hub element, an annular covering disc positioned on the front side, an intake opening formed on the front side, a support disc positioned on the rear side, blades extending substantially radially from the hub element towards the peripheral edge, and outflow openings formed in the region of the peripheral edge. A first outer diameter of a radially outer edge of the annular covering disc is greater than a second outer diameter of a radially outer edge of the support disc. Openings are formed in the annular covering disc, wherein the openings are positioned between the radially outer edge of the annular covering disc having the first outer diameter and a radially inner edge of the annular covering disc having a first inside diameter.

A plurality of water heaters are connected in parallel with respect to a hot water supply path, and each of the plurality of water heaters has an exhaust path connected to an exhaust path assembly. Each of a plurality of sensing units is configured to be shifted from an electrically conducting state to an electrically non-conducting state when each of the plurality of sensing units senses an abnormal condition about air supply or exhaust. A series circuit of the plurality of sensing units is electrically connected in series to a resistance element between the power supply line and the ground line. The controller is configured to monitor an abnormal condition about air supply or exhaust based on a voltage on a node between the series circuit and the resistance element.

Systems and methods for counter-flow heat reduction cycles are disclosed. Embodiments may include a gas furnace having a combustion air pipe, an exhaust air pipe, and a heat exchanger coupled to the combustion air pipe and the exhaust air pipe, the heat exchanger having a heat exchanger tube and an induced draft blower configured to direct air toward the heat exchanger tube, where the air flows over the heat exchanger tube and into the exhaust air pipe. The gas furnace may include a controller configured to determine a call for heat, activate the induced draft blower during a normal heating operation, determine that the call for heat is no longer present, determine that at least 70 seconds have elapsed since determining that the call for heat is no longer present, and deactivate the induced draft blower.

The object of the present invention is a ventilated hob (400) comprising a motor-driven fan (V) adapted to provide high pressure air to two or more burners (BRNi) thereof, each of said two or more burners (BRNi) at least comprising means (VG, 211; 211.a, 211.b) for supplying and regulating the flow of fuel gas (Q.sub.GAS) in input into each of said two or more burners (BRNi), means (VP; 101; UG) for supplying the flow of combustion air (Q.sub.AIR) in input into each of said two or more burners (BRNi), able to mix with said fuel gas, shut-off valves of the flow of said combustion air, an electronic unit (.sub.CMD) for controlling said air flow (Q.sub.AIR).

The air flow (Q.sub.AIR) varies as a function of said flow of fuel gas (Q.sub.GAS) in input into each of said two or more burners (BRNi) so as to ensure a gas-air mixture with a stoichiometric or substantially stoichiometric ratio without the need of input of secondary air from the outside, said variation of air flow (Q.sub.AIR) being obtained by varying the pressure of the combustion air in said sealed circuit (CA1, 405, 407) inside said hob (400).

Said pressure is intermediate to the single pressures that each active burner (BRNi) should have.

A plurality of water heaters are connected in parallel with respect to a hot water supply path, and each of the plurality of water heaters has an exhaust path connected to an exhaust path assembly. Each of a plurality of sensing units is configured to be shifted from an electrically conducting state to an electrically non-conducting state when each of the plurality of sensing units senses an abnormal condition about air supply or exhaust. A series circuit of the plurality of sensing units is electrically connected in series to a resistance element between the power supply line and the ground line. The controller is configured to monitor an abnormal condition about air supply or exhaust based on a voltage on a node between the series circuit and the resistance element.

A combination boiler provides heated water to a boiler loop and heated domestic hot water (DHW) to a DHW loop. A primary heat exchanger is connected to the boiler loop. A burner provides heat to the primary heat exchanger and an input fan supplies a fuel and air mixture to the burner. A secondary heat exchanger transfers heat energy from the boiler loop to a domestic water loop. A controller determines a boiler loop flow rate. The controller measures an input temperature of the boiler loop, an output temperature of the boiler loop, and a DHW output temperature of the domestic water loop. The controller determines a DHW input temperature and estimates a DHW flow rate. The input fan speed is initiated or operated according to a required heat output of the burner corresponding to the DHW flow rate.