A grid-energy firming process and a grid energy firming system. The process comprises alternating between a process for generating electrical energy, and a process for generating gaseous fuels in response to the energy demands of a grid energy system. The system comprises a reactor containing a carbonaceous fuel, and a heat exchanger to extract heat from the flue gas and/or gaseous fuel.

Methods and related systems for operating a furnace are disclosed. In an embodiment, the method includes activating a burner assembly and a first fan of the furnace to combust fuel and air and circulate combustion gases along a flow path extending through a heat exchanger of the furnace. In addition, the method includes operating a second fan of the furnace to circulate air across an external surface of the heat exchanger of the furnace and produce a conditioned airflow. Further, the method includes monitoring one or more parameters of a motor of the second fan indicative of an airflow rate of the conditioned airflow, and deactivating the burner assembly, whereby combustion of the fuel and air in the furnace ceases, in response to the one or more parameters indicating that the airflow rate is less than a minimum airflow rate.

A fire pit comprises a fuel source connector and at least one fuel outlet. A fuel conduit conveys fuel from the fuel source connector to the fuel outlet, and there is at least one sensor for detecting the presence of unburned fuel outside the fuel conduit. Further, the fire pit includes a fuel control mechanism for stopping or modulating the conveyance of fuel when the sensor detects the presence of unburned fuel.

A gas furnace according to an embodiment of the present disclosure includes: a mixer for mixing air and a fuel gas, which are introduced through an intake pipe and a manifold, respectively, to form a mixture; a mixing pipe through which the mixture, having passed through the mixer, flows; a burner assembly for producing a combustion gas by burning the mixture having passed through the mixing pipe; a heat exchanger through which the combustion gas flows; an exhaust pipe through which an exhaust gas, as the combustion gas having passed through the heat exchanger, is discharged outside of the gas furnace; and an inducer for inducing a flow of a fluid through the intake pipe, the mixer, the mixing pipe, the burner assembly, the heat exchanger, and the exhaust pipe. In this case, the mixer has a front end connected to the intake pipe, a rear end connected to the mixing pipe, and a side surface connected to the manifold.

A furnace including: a blower assembly compartment; a blower assembly located within the blower assembly compartment; a blower motor located within the blower assembly compartment, the blower motor operably connected to a fan of the blower assembly; an induced draft blower; an inducer motor operably connected to the induced draft blower; and a dual motor controller located within the blower assembly compartment, the dual motor controller being configured to independently control at least one of a torque or a speed of the blower motor and the inducer motor.

A stove for indoor use includes a housing having a bottom wall, a top wall and one or more side walls defining a combustion chamber adapted to retain a fire, and an air supply system for supplying air to the combustion chamber. The air supply system includes a primary air conduit for supplying air to the combustion chamber from below through the bottom wall and a secondary air conduit for supplying air to the combustion chamber from above. A valve is arranged in the primary air conduit or in a branching between the primary and secondary air conduits. The valve is controlled by a bimetal whereby the valve is in a maximum open position when the prevailing temperature is below a first predetermined temperature during start-up of a fire and in a maximum closed position when the prevailing temperature is above a second predetermined temperature after start-up of the fire.

One or more techniques and/or systems are disclosed for a portable heater that may be used in an area used for human occupancy, to provide heat to that area. Such a heater can be portable, and comprise an environmental detector that senses ambient air conditions, and may provide data used to shut down the heater in threshold conditions. In one implementation, a portable heater for use in high altitudes can comprise a housing configured for portability, in which a combustion region and a fuel supply component are disposed. The heater can comprise an environmental detector with a flameless sensor configured to detect an ambient level of a constituent of the atmosphere, and generate a signal indicative of the constituent level; and a sensor interface that can control flow of fuel from the fuel supply, based at least upon a signal received from the sensor.

One or more techniques and/or systems are disclosed for a vent-free heater that may be installed in an area used for human occupancy, to provide heat to that area. Such a heater can comprise an environmental detector that senses ambient air conditions, and may provide data used to shut down the heater in predetermined threshold condition. In one implementation, a vent-free heater for installation in high altitudes can comprise a combustion region and a fuel supply component. The heater can comprise an environmental detector with a flameless sensor configured to detect an ambient level of a constituent of the atmosphere and generate a signal indicative of the constituent level; and a sensor interface that can control flow of fuel from the fuel supply, based at least upon a signal received from the sensor.

A control system for a solid fuel combustion appliance, e.g., a wood burning stove, includes a temperature sensor for sensing an output temperature of the appliance. A controller receives the output temperature and controls a damper associated with air flow through the stove to maintain a predetermined temperature. The system also includes a detector that senses certain conditions of the solid fuel, e.g., wood, that is burned by the stove. When additional fuel is added to the appliance, the system temporarily encourages initial combustion of the new fuel, before returning to maintaining the predetermined temperature.

A method of determining presence of a flame in a furnace of a heating, ventilation, and air conditioning (HVAC) system. The method comprises determining, using a controller, whether a processor signal (G) is active, responsive to a determination that the processor signal (G) is active, determining, using the controller prior to assertion of a flame-test input control signal, an output state of a first comparator, responsive to a determination that the output state of the first comparator is high, determining, using the controller prior to assertion of the flame-test input control signal, an output state of a second comparator, and responsive to a determination that the output state of the second comparator is low, transmitting, using the controller, a notification that a flame is present.