A hydraulic construction unit for a heating facility or air-conditioning facility, includes a return connection (20) and a first feed connection (16) for a heating circuit (6), with a heat source outlet (12) fluid conducting connected to the return connection. A heat source inlet (14) is fluid conducting connected to the first feed connection and to a circulation pump assembly (28) in a flow path between the return connection and the heat source outlet (12) or in a flow path between the heat source inlet and the first feed connection. A second feed connection (18) for a second heating circuit (8), is fluid conducting connected to the heat source inlet and to the return connection. A mixing valve (54) is arranged in a flow path from the heat source inlet to the second feed connection and/or in a flow path from the return connection to the second feed connection.

A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

The present disclosure discloses a combustion chamber and a combustion apparatus. The combustion chamber includes: a first surrounding plate located on an outer side and a second surrounding plate located on an inner side. A combustion cavity is defined by the second surrounding plate. The first surrounding plate and the second surrounding plate are spaced apart from each other to define at least one air duct in communication with the combustion cavity. Each of the at least one air duct has an air inlet hole formed in the first surrounding plate, and an air outlet hole formed in the second surrounding plate.

A water supply system includes a main water tank that is configured to store water and includes a heater to heat the stored water to close to but below a boiling temperature thereof, to provide main heated water. A dispenser water tank receives a portion of the main heated water, and is free of any heating elements to add heat to the water stored therein, and providing dispensable heated water. A water mixer includes a first pipe for receiving the dispensable heated water from the dispenser tank and a second pipe for receiving utility water from a faucet that supplies utility-provided water, with a mixing chamber from which the waters from the first pipe and the second pipe are dispensed and/or in which these waters are admixed.

The flameless heater system includes an energy source comprising a diesel engine configured to create volumes of air, a hydraulic system to control engine loading for heat generation and for air moving, and a control system, operatively coupled with the energy source and the hydraulic system to control at least one of a speed of the diesel engine, a loading of the diesel engine, or a fan speed.

A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

A method for controlling an on-demand high volume capable fluid heating system that supplies a total heating power at a turndown ratio and a total flowrate of a fluid supply, the fluid heating system comprising a plurality of heat exchangers fluidly connected in parallel, each of the plurality of heat exchangers comprising: a fluid conductor, wherein each of the plurality of heat exchangers contributes to the total heating power and a portion of the total flowrate of the fluid supply through the fluid conductor; an inlet conductor configured to connect the fluid supply to the plurality of heat exchangers; an outlet conductor configured for receiving the fluid supply downstream of the plurality of heat exchangers; an auxiliary conductor connecting the inlet conductor at a first location and the outlet conductor, the auxiliary conductor comprising a modulating valve; and a pump disposed downstream from the first location on the inlet conductor.

A transfer tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity, where the at least one wall further has a first end and a second end. The first end can be configured to couple to a terminus of a heat exchanger of the thermal transfer device. The second end can be configured to couple to a collector box of the thermal transfer device. At least a portion of the at least one wall can be disposed in a vestibule of the thermal transfer device. The cavity can be configured to simultaneously receive a first fluid that flows from the first end to the second end and a second fluid that flows from the second end to the first end.

A heating apparatus, in particular for recreational vehicles like campers or caravans, comprises a heating unit and two separate heat exchanging units, which are coupled to the heating unit in parallel with each other. The heating unit comprises one burner for each heat exchanging unit, and at least one combustion air fan unit configured to supply the burners with combustion air. The burners are configured to burn fuel gas or liquid further supplied to each of the burners together with the combustion air received from the combustion air fan unit to get hot exhaust gasses. The heat exchanging units and are configured to receive the exhaust gasses from the burners, and to transfer heat from the exhaust gasses to fluids to be heated, provided within the heat exchanging units. The heat exchanging units are positioned in parallel with each other side by side on one side of the heating unit. Furthermore, the present invention refers to a recreational vehicle with such a heating apparatus.

A heating apparatus is disclosed. The heating apparatus comprises a PTC heating element, a first electrode, a second electrode, a first protection layer, a second protection layer, a first interlayer, and a second interlayer. A hardness of the first protection layer is greater than that of the first interlayer. A hardness of the second protection layer is greater than that of the second interlayer.