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.

To detect an abnormality without a limit switch, a space and water heating apparatus includes external and internal circulation channels, including a shared portion, to respectively circulate a heating medium through space heating equipment (20) and a water-heating heat exchanger (28), a first temperature sensor (25) that detects a temperature of the heating medium heated in the shared portion, and a second temperature sensor (35) that detects a temperature of hot water produced with the heat exchanger. A switch controller (40) controls a circulation switcher (29) to switch between the circulation channels. A storage (40a) prestores, in association with a mode of the circulation switcher, a detection value from the second temperature sensor expected when the circulation switcher operates normally. An abnormality detector (40) detects an abnormality in the circulation switcher in response to the actual detection value being different from the expected detection value associated with the instructed mode.

To detect an abnormality without a limit switch, a space and water heating apparatus includes external and internal circulation channels, including a shared portion, to respectively circulate a heating medium through space heating equipment (20) and a water-heating heat exchanger (28), a first temperature sensor (25) that detects a temperature of the heating medium heated in the shared portion, and a second temperature sensor (35) that detects a temperature of hot water produced with the heat exchanger. A switch controller (40) controls a circulation switcher (29) to switch between the circulation channels. A storage (40a) prestores, in association with a mode of the circulation switcher, a detection value from the second temperature sensor expected when the circulation switcher operates normally. An abnormality detector (40) detects an abnormality in the circulation switcher in response to the actual detection value being different from the expected detection value associated with the instructed mode.

The present disclosure provides a control method of the heat pump system and the heat pump system, wherein the method includes: determining priority information of an operation mode, wherein the operation mode includes: a hot water production mode and an air conditioning mode; controlling the heat pump system to operate according to an operation mode with the higher priority information, and acquiring the corresponding operation parameter; determining whether the operation parameter satisfies a preset condition; and controlling the heat pump system to switch to operate in the operation mode with the lower priority information, if yes.

The present disclosure provides a control method of the heat pump system and the heat pump system, wherein the method includes: determining priority information of an operation mode, wherein the operation mode includes: a hot water production mode and an air conditioning mode; controlling the heat pump system to operate according to an operation mode with the higher priority information, and acquiring the corresponding operation parameter; determining whether the operation parameter satisfies a preset condition; and controlling the heat pump system to switch to operate in the operation mode with the lower priority information, if yes.

Provided is an air conditioning system. The air conditioning system includes a heat pump provided to heat or cool a circulating refrigerant, an air heating device provided to burn a fuel so as to heat circulating water so that air is heated by the heated water, and an intermediate heat exchanger provided to exchange heat between the refrigerant and the water.

Provided is an air conditioning system. The air conditioning system includes a heat pump provided to heat or cool a circulating refrigerant, an air heating device provided to burn a fuel so as to heat circulating water so that air is heated by the heated water, and an intermediate heat exchanger provided to exchange heat between the refrigerant and the water.

A heating medium circulation apparatus promptly detects an overheating abnormality of a heating medium caused by insufficient circulation. The heating medium is pumped by a pump in a predetermined direction in a closed-loop circuit connecting a heater and a heat dissipator. An outgoing temperature and a return temperature of the heating medium flowing out of and into the heater are detected. When a heat dissipation-based operation starts, the pump is activated, and heating is started. Heating is temporarily stopped when the outgoing temperature reaches a heating stop temperature. Heating is resumed when the outgoing temperature falls below a heating resumption temperature. An additional condition that the difference between the outgoing and return temperatures is less than a determination value can be added to the condition for resuming heating. An overheating abnormality is detected when the additional condition remains unsatisfied until a determination time elapses after heating is stopped.

A heating medium circulation apparatus promptly detects an overheating abnormality of a heating medium caused by insufficient circulation. The heating medium is pumped by a pump in a predetermined direction in a closed-loop circuit connecting a heater and a heat dissipator. An outgoing temperature and a return temperature of the heating medium flowing out of and into the heater are detected. When a heat dissipation-based operation starts, the pump is activated, and heating is started. Heating is temporarily stopped when the outgoing temperature reaches a heating stop temperature. Heating is resumed when the outgoing temperature falls below a heating resumption temperature. An additional condition that the difference between the outgoing and return temperatures is less than a determination value can be added to the condition for resuming heating. An overheating abnormality is detected when the additional condition remains unsatisfied until a determination time elapses after heating is stopped.

A combination heating system and method, including a combustion chamber, a combustion heat exchanger receiving heat from the combustion chamber, and a thermal storage reservoir. The combustion heat exchanger includes first fins extending outward from the combustion heat exchanger, and at least some of the first fins may have a profile that is at least partially curved or S-shaped. The thermal storage reservoir has an outer wall and an inner wall, and may contain a fluid such as glycol between the outer wall and the inner wall. The inner wall forms a hollow passageway through which the combustion heat exchanger extends. The thermal storage reservoir also includes second fins extending inward from the inner wall toward the combustion heat exchanger. The first fins interdigitate with the second fins in a spaced-apart manner such that airgaps exist between adjacent interdigitated ones of the first fins and the second fins.