Disclosed are a gas furnace and an air conditioner having the same. The gas furnace includes: a burner for burning fuel; a manifold providing the fuel to an entry of the burner; a heat exchanger spaced apart from an exit of the burner and providing a passage for combustion gas generated by the burner; an inducer for causing a fluid to flow through the burner and the heat exchanger; a blower for causing a flow of air passing around the heat exchanger; and an air shutter positioned between the manifold and the entry of the burner. The air shutter includes: a housing having an inner space that communicates with the manifold and the entry of the burner; and a primary hole formed to penetrate the housing and able to be opened and closed.

Disclosed are a gas furnace and an air conditioner having the same. The gas furnace includes: a fuel valve; a manifold providing a passage of fuel passing through the fuel valve; a plurality of burners provided to burn fuel provided from the manifold and spaced apart from each other in one direction; a plurality of heat exchangers providing a passage of combustion gas generated by the plurality of burners; and a blower for causing a flow of air passing around the heat exchanger. The manifold includes: a first tube having one end connected to the fuel valve and forming a first passage; a second tube extending in the one direction, forming a second passage, and facing at least one of the plurality of burners; a third tube extending in the one direction, forming a third passage, and facing remaining burners of the plurality of burners; and a three-way valve connected to the first tube, the second tube, and the third tube.

A room heater is operated on receiving an on-command from a thermostat when a detected temperature detected by a second room-temperature detector falls below a first reference temperature, and is stopped on receiving an off-command when the temperature detected by the second room-temperature detector is above a second reference temperature that is set higher than the first reference temperature or when the thermostat is manually operated to be switched off. A setting temperature for temperature control to be carried out when the on-command is received again is updated according to a difference between the set temperature and the temperature detected by the first room-temperature detector on receiving the off-command. When the off-command is received before passing a predetermined period of time after receiving the on-command, the updating of the set temperature is prohibited if the temperature detected by the first room-temperature detector is below a predetermined minimum lower reference temperature.

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 heating system including at least one louver coupled with the housing of a heater including a blade and end caps on the blade for holding each louver in a fixed position during operation of the heater assembly, but also releasing the louver for adjustment in positioning relative to the axis of rotation of the louver to change air flow direction or other characteristics as desired.

A gas furnace includes a mixing pipe through which a mixture formed by mixing fuel gas and air flows; a burner assembly that generates combustion gas by burning the mixture that passed through the mixing pipe; and a heat exchanger through which the combustion gas flows. In this case, the burner assembly includes a burner in which flame generated when the mixture is burned is seated; and a mixing chamber that mediates delivery of the mixture from the mixing pipe to the burner, thereby significantly reducing NOx emission.

The present invention is directed to a heat and energy recovery assembly, system and method. The heat and energy recovery assembly and system may include an insulated chamber for effectuating heat and energy exchange between a primary heat recovery exchanger and the reaction products of fossil fuel combustion gases, waste products, and air. The heat and energy recovery assembly and system are particularly useful on furnace systems.

A heat exchanger arrangement, especially for a vehicle heater, includes a pot-like heat exchanger housing (12) with an inner wall (22, 24) and with an outer wall (18, 20). A heat carrier medium flow space is formed between the inner wall (22, 24) and the outer wall (18, 20). A first flow opening (54) is provided on the outer wall (18, 20) and, adjoining this, a pump housing (58) made integrally with the outer wall (18, 20) for a heat carrier medium pump is provided.

A method is provided for controlling combustion in a modulating gas furnace. The method includes receiving an indication of a firing rate setpoint for a burner assembly, and applying the firing rate setpoint to first and second continuous functions that map the firing rate setpoint to air-to-fuel ratio and combustion system pressure setpoints. A variable-speed draft inducer blower is set to drive to a combustion system pressure setpoint, and the modulating gas valve is controlled during combustion in the combustion system. In this regard, a combustion system pressure measurement is obtained and applied to an inverse of the first continuous function that outputs an adjusted firing rate for the combustion system pressure measurement. The adjusted firing rate is applied to a third continuous function that maps the firing rate to gas valve position, and outputs a gas valve position to which the modulating gas valve is set.