A method for manufacturing a counter flow total heat exchanger is disclosed. The method for manufacturing a counter flow total heat exchanger, according to the present invention, comprises the steps of: inserting, between a pair of rollers (210, 210a) having protrusions formed on the surface thereof, a first paper having a first width, so as to form same into a single face corrugated cardboard sheet (T) having flow paths (111c, 121c); attaching the corrugated cardboard sheet (T) to a middle region of a second paper having a second width that is wider than the first width; cutting, into a length corresponding to guide corrugated cardboards (111, 121), the second paper to which the corrugated cardboard sheet (T) is attached; and cutting the second paper by means of a liner (130) having triangular resin tube coupling surfaces (133) formed on both sides of the cut guide corrugated cardboards (111, 121).

A compact heat recovery unit which includes separate and distinct thermal cores housed in their own channels. Each thermal core and its respective channel is moved at intervals. When a thermal core and its channel is inserted into a high temperature fluid flow, the thermal core absorbs the heat. When this heated thermal core and its channel is then later inserted into a low temperature fluid flow, the low temperature fluid is preheated by the heated thermal core. This operation is repeated with at least two independent thermal cores and their respective channels to maintain substantially continual pre-heating of received low temperature fluid. Similarly, the compact heat recovery unit can be used in a cooling application where pre-cooling of received higher temperature fluid is executed.

A hybrid heating system is disclosed. The hybrid heating system includes a compressor that is configured to compress refrigerant. The hybrid heating system further includes a first heat exchanger that is configured to adjust a temperature of water by exchanging heat between the water and refrigerant compressed by the compressor. The hybrid heating system further includes a second heat exchanger that is configured to evaporate refrigerant by exchanging heat exchange with exterior air. The hybrid heating system further includes a first boiler heat exchanger that is configured to increase a temperature of water using heat generated by combustion. The hybrid heating system further includes a second boiler heat exchanger that is configured to exchange heat between exhaust gas discharged from the first boiler heat exchanger and refrigerant flowing into the second heat exchanger.

A method of forming a membrane panel configured to be secured within an energy exchange assembly may include forming an outer frame defining a central opening, and integrating a membrane sheet with the outer frame. The membrane sheet spans across the central opening, and is configured to transfer one or both of sensible energy or latent energy therethrough. The integrating operation may include injection-molding the outer frame to edge portions of the membrane sheet. Alternatively, the integrating operation may include laser-bonding, ultrasonically bonding, heat-sealing, or the like, the membrane sheet to the outer frame.

A method and apparatus for recovering energy from exhaust air in a standard kitchen ventilation hood. One or more removeable energy recovery modules comprised of a plurality of heat pipes is mounted above the hot exhaust gases. Working fluid within the heat pipes transfers heat to the makeup air, warming it before it is returned to the kitchen.

A compact heat recovery unit which includes separate and distinct thermal cores housed in their own channels. Each thermal core and its respective channel is moved at intervals. When a thermal core and its channel is inserted into a high temperature fluid flow, the thermal core absorbs the heat. When this heated thermal core and its channel is then later inserted into a low temperature fluid flow, the low temperature fluid is preheated by the heated thermal core. This operation is repeated with at least two independent thermal cores and their respective channels to maintain substantially continual pre-heating of received low temperature fluid. Similarly, the compact heat recovery unit can be used in a cooling application where pre-cooling of received higher temperature fluid is executed.

A heat exchange system for commercial kitchen installations, having a dedicated plenum to receive combustion emissions separate from cooking emissions, where the plenum has a heat exchange structure that efficiently and directly draws heat from the combustion emissions. The plenum heat exchange structure reduces the air volume that a ventilation hood covering the kitchen appliances needs to process and filter, while concurrently obtaining heat from combustion emissions without interference from cooking emission effluents such as grease, smoke, or particulate matter. Heat drawn out of the combustion emissions can be stored in a thermal reservoir for powering other parts of the commercial kitchen or other uses. The diverted airstream from combustion emissions, once passed through the heat exchange structure, can further ventilate through an additional heat exchanger, to provide tempered air to an interior location, such as the commercial kitchen via an air supply duct in the cooking emission ventilation hood.

A heat exchanger for an apparatus including a burner has at least one tube extending along a centerline from an inlet end adjacent the burner to an outlet end. A plurality of indentations is formed in the tube adjacent the inlet end and extend radially inward towards the centerline. The indentations are formed in opposing pairs extending towards one another to a depth sufficient to create turbulent fluid flow through the inlet end of the tube.

A method and apparatus for recovering energy from exhaust air in a standard kitchen ventilation hood. One or more removeable energy recovery modules comprised of a plurality of heat pipes is mounted above the hot exhaust gases. Working fluid within the heat pipes transfers heat to the makeup air, warming it before it is returned to the kitchen.

A hybrid heating system is disclosed. The hybrid heating system includes a compressor that is configured to compress refrigerant. The hybrid heating system further includes a first heat exchanger that is configured to adjust a temperature of water by exchanging heat between the water and refrigerant compressed by the compressor. The hybrid heating system further includes a second heat exchanger that is configured to evaporate refrigerant by exchanging heat exchange with exterior air. The hybrid heating system further includes a first boiler heat exchanger that is configured to increase a temperature of water using heat generated by combustion. The hybrid heating system further includes a second boiler heat exchanger that is configured to exchange heat between exhaust gas discharged from the first boiler heat exchanger and refrigerant flowing into the second heat exchanger.