A multi-heater heating system including a first heater configured for expelling air through a first side surface of the first heater; and a second heater configured to be disposed and stacked above the first heater.

A multi-heater heating system including a first heater configured for expelling air through a first side surface of the first heater; and a second heater configured to be disposed and stacked above the first heater.

A controller (2a) sets a target setting temperature for an air-conditioning space 10, compares a value obtained by subtracting an outdoor temperature detected by an outdoor temperature sensor 9 from the target setting temperature, with a first threshold related to the value, compares a value obtained by subtracting the outdoor temperature from an indoor temperature detected by an indoor temperature sensor 8, with a second threshold related to the value, compares a value obtained by subtracting a heat load in the air-conditioning space 10 from a cooling capacity, with a third threshold related to the value, and controls operation of a heat pump type air-conditioning device 2 and a ventilating device 3 on the basis of these comparison results. The first threshold, the second threshold, and the third threshold are set in accordance with the number of people detected by a human detection sensor 5.

A controller (2a) sets a target setting temperature for an air-conditioning space 10, compares a value obtained by subtracting an outdoor temperature detected by an outdoor temperature sensor 9 from the target setting temperature, with a first threshold related to the value, compares a value obtained by subtracting the outdoor temperature from an indoor temperature detected by an indoor temperature sensor 8, with a second threshold related to the value, compares a value obtained by subtracting a heat load in the air-conditioning space 10 from a cooling capacity, with a third threshold related to the value, and controls operation of a heat pump type air-conditioning device 2 and a ventilating device 3 on the basis of these comparison results. The first threshold, the second threshold, and the third threshold are set in accordance with the number of people detected by a human detection sensor 5.

A geothermal system having a flow station connected to a heat pump that is connected to a heat pump that is connected to a flow vector assembly. The flow vector assembly is connected to a heating coil and a cooling coil disposed within the ductwork of a furnace. The flow vector assembly may also be connected to a flow helix heat exchanger assembly.

A geothermal system having a flow station connected to a heat pump that is connected to a heat pump that is connected to a flow vector assembly. The flow vector assembly is connected to a heating coil and a cooling coil disposed within the ductwork of a furnace. The flow vector assembly may also be connected to a flow helix heat exchanger assembly.

Provided is a heat pump device configured to collect heat both from outside air and another heat source. A controller calculates heat exchange amounts with use of heat exchange performance of each of an air heat-source heat exchanger and an underground heat-source heat exchanger in addition to an outside air temperature and an underground temperature. Then, in switching between a simultaneous operation of causing refrigerant to flow through both of the air heat-source heat exchanger and the underground heat-source heat exchanger and a single operation of selecting the air heat-source heat exchanger or the underground heat-source heat exchanger to cause refrigerant to flow therethrough, the controller selects a heat source having a larger calculated heat exchange amount. In this manner, an appropriate heat source suitable for operation conditions can be selected.

Provided is a heat pump device configured to collect heat both from outside air and another heat source. A controller calculates heat exchange amounts with use of heat exchange performance of each of an air heat-source heat exchanger and an underground heat-source heat exchanger in addition to an outside air temperature and an underground temperature. Then, in switching between a simultaneous operation of causing refrigerant to flow through both of the air heat-source heat exchanger and the underground heat-source heat exchanger and a single operation of selecting the air heat-source heat exchanger or the underground heat-source heat exchanger to cause refrigerant to flow therethrough, the controller selects a heat source having a larger calculated heat exchange amount. In this manner, an appropriate heat source suitable for operation conditions can be selected.

A heat pump apparatus includes a refrigerant circuit for circulating combustible refrigerant, and a load unit to be provided in a room and configured to accommodate a load side heat exchanger. The load side heat exchanger allows heat exchange between the combustible refrigerant and a liquid heat medium. The load unit includes a fan, an air inlet for sucking in air from the room, and an air outlet for blowing out the air, sucked in from the air inlet, to the room. The air outlet is provided at a position of a height different from the height of the air inlet.

A heat pump apparatus includes a refrigerant circuit for circulating combustible refrigerant, and a load unit to be provided in a room and configured to accommodate a load side heat exchanger. The load side heat exchanger allows heat exchange between the combustible refrigerant and a liquid heat medium. The load unit includes a fan, an air inlet for sucking in air from the room, and an air outlet for blowing out the air, sucked in from the air inlet, to the room. The air outlet is provided at a position of a height different from the height of the air inlet.