A heat recovery system for recovering waste heat from exhaust gases that are expelled through a flue that are generated as a byproduct from a heating system, comprises a venting arrangement that connects to the flue from the heating system and a motorized damper to direct the exhaust gases from the flue through the venting arrangement to an intake plenum. The intake plenum directs the exhaust gases to a heat exchanger that comprising a series of serpentine conduits between which the exhaust gases pass through. The heat exchanger is connected to exhaust plenum which is in turn connected to an exhaust fan that draws the exhaust gasses through the heat recovery system. The heat exchanger further comprises a series of inlet ports and outlet ports that add and remove coolant to the serpentine conduits at selected temperatures.

A gas furnace includes: a combustion part in which a fuel gas is burnt to generate a combustion gas; a heat exchanger having a gas flow path through which the combustion gas flows; a blower configured to blow air around the heat exchanger; and an inducer configured to discharge the combustion gas from the heat exchanger, wherein the heat exchanger includes: at least one single path in which a single gas flow path is formed; a single-multiple return bend configured to communicate with the single path and convert a flow direction of the combustion gas; and at least one multiple path having a plurality of paths that communicate with the single-multiple return bend and form multiple gas flow paths.

One aspect of this disclosure provides a heat exchanger that comprises a first panel half coupled to a corresponding second panel half that form a passageway having at least a first chamber adjacent an inlet end of the passageway and a second chamber and overlapping interference patterns formed in each of the first and second panel halves that extend along at least a portion of the length of the passageway and located between at least the first and second chambers.

An exhaust gas latent-heat recovery device includes: a heat transfer tube disposed inside a duct through which exhaust gas flows, the heat transfer tube having a water supply inlet into which water to be heated for recovering latent heat of the exhaust gas is supplied and a water supply outlet through which the water to be heated is discharged; and a water supply control part configured to control supply of the water to be heated to the water supply inlet. The water supply control part is configured to control supply of the water to be heated from the water supply inlet so that an outlet temperature being a temperature of the water to be heated at the water supply outlet is at a set temperature.

A condensing heat exchanger (100) capable of lowering a requirement for a fan and a water heater having the same, wherein the condensing heat exchanger (100) comprises: a heat exchanger housing (110) having a flue gas inlet (101) and a flue gas outlet (102); and a heat exchange unit (104) located within the heat exchanger housing (110), wherein a sidewall flue gas exhaust channel (105) communicated with the flue gas outlet (102) is provided between the heat exchange unit (104) and an inner sidewall of the heat exchanger housing (110), the heat exchange unit (104) surrounds a flue gas inlet channel (103) communicated with the flue gas inlet (101), the sidewall flue gas exhaust channel (105) surrounds the heat exchange unit (104), and the heat exchange unit (104) is internally provided with a heat exchange flue which communicates the flue gas inlet channel (103) with the sidewall flue gas exhaust channel (105).

An exhaust conduit for neutralizing condensate from high efficiency gas storage water heaters is provided. The exhaust conduit includes an inlet configured to be coupled to an exhaust outlet of the heater, an outlet configured to be coupled to an exhaust vent, and a condensate chamber having an interior in fluidic communication with the inlet and the outlet. The condensate chamber has a lower portion configured to receive a neutralizer and an upper portion having a service port configured to provide access to the lower portion of the condensate chamber. The condensate chamber further includes a fluid outlet for draining the neutralized condensate via a drain line. The exhaust conduit has one or more ridges disposed in the chamber that are arranged to define a channel for directing condensate from the inlet across the neutralizer toward the fluid outlet.

A condensing boiler condensate discharge device includes a hollow body having a peripheral wall, a first longitudinal end and a second longitudinal end. An inflow opening is provided in the peripheral wall and extends starting from the first longitudinal end in the direction of the second longitudinal end. A drain opening is provided in the peripheral wall. A separating wall is provided within the hollow body and extends from the first longitudinal end in the direction of the second longitudinal end and has a free end. The separating wall divides the hollow body into a condensate receiving channel, and a condensate discharge channel. The condensate receiving channel and the condensate discharge channel are flow-connected to each other via a passage. The drain opening and the inflow opening are arranged to be overlapping with an overlap length as viewed in the longitudinal direction.

Aspects of the invention are directed to condensate traps having a back portion and a front portion. The back portion includes a first passage enclosed between the first wall, a second wall, and a back wall. A first opening in the back portion connects the first wall and the second wall with a first float placed over the first opening and does not travel below the first opening and is prevented from leaving the first passage by a first constriction. The front portion of the condensate trap includes a second passage enclosed between the third wall and the fourth wall. A second opening connects the third wall and the fourth wall in the front portion and a second float is placed below the second opening such that it does not travel through the second opening and is prevented from falling below a predetermined level by a second constriction.

A heating, ventilating, and air conditioning (HVAC) system includes a furnace having a primary heat exchanger and a secondary heat exchanger, where the primary heat exchanger and the secondary heat exchanger form a heat exchange relationship between an airflow and an exhaust gas, and where the primary heat exchanger is positioned upstream of the secondary heat exchanger, a burner configured to generate the exhaust gas, a sensor configured to monitor an ambient temperature, and a control system configured to receive feedback from the sensor, compare the feedback to a threshold, operate the furnace in a first mode when the ambient temperature exceeds the threshold, and operate the furnace in a second mode when the ambient temperature is at or below the threshold, where the furnace operates above a condensation temperature when in the second mode, such that the exhaust gas does not condense when operating in the second mode.

A heat exchanger includes a lamellar structure of a plurality of parallel heat exchange elements with an intermediate air gap between each pair of adjacent heat exchange elements. Along a longitudinal direction of the lamellar structure the heat exchange elements is interconnected in a top portion of the lamellar structure that forms an inlet channel through the heat exchange elements and in a bottom portion of the lamellar structure that forms an outlet channel through the heat exchange elements. The heat exchange elements form parallel channels between the inlet and the outlet channels. In the outlet channel, the heat exchanger includes a filler body, that is filling up a lower level of the outlet channel and forms a floor along the longitudinal direction of the lamellar structure.