A multi-mode, bi-directional cascade heat pump system, according to some examples, includes at least two chillers each being part of a unidirectional refrigerant circuit. The system includes heat exchangers each of which are dedicated to operate as just a condenser or as just an evaporator, regardless of the system's operating mode. In some modes, a secondary fluid transfers heat between the condenser of one chiller and the evaporator of another chiller before the fluid returns to a secondary fluid source such as, for example, a geothermal borefield or a conventional water source. In some embodiments, fluid is withdrawn from a borefield by way of a pump having a speed that varies to maintain a desired fluid temperature and/or a desired heat transfer rate at the borefield. The heat pump system includes means for minimizing flow through the borefield and for minimizing unnecessary mixing of relatively high and low temperature fluid.

A multi-mode, bi-directional cascade heat pump system, according to some examples, includes at least two chillers each being part of a unidirectional refrigerant circuit. The system includes heat exchangers each of which are dedicated to operate as just a condenser or as just an evaporator, regardless of the system's operating mode. In some modes, a secondary fluid transfers heat between the condenser of one chiller and the evaporator of another chiller before the fluid returns to a secondary fluid source such as, for example, a geothermal borefield or a conventional water source. In some embodiments, fluid is withdrawn from a borefield by way of a pump having a speed that varies to maintain a desired fluid temperature and/or a desired heat transfer rate at the borefield. The heat pump system includes means for minimizing flow through the borefield and for minimizing unnecessary mixing of relatively high and low temperature fluid.

A heat pump system provides at least six modes of heating, cooling, and/or domestic water heating operation, where domestic water heating may occur concurrently with heating or cooling a space in a structure. The heat pump system comprises a desuperheater positioned downstream of the compressor and operable as a desuperheater, a condenser or an evaporator, a source heat exchanger operable as either a condenser or an evaporator, a load heat exchanger operable as either a condenser or an evaporator, a reversing valve positioned downstream of the desuperheater heat exchanger and configured to alternately direct refrigerant flow from the desuperheater heat exchanger to one of the load heat exchanger and the source heat exchanger and to alternately return refrigerant flow from the other of the load heat exchanger and the source heat exchanger to the compressor, and an expansion valve positioned between the load heat exchanger and the source heat exchanger.

There is disclosed a foundation system for providing support to a structural load thereon and geothermal heat exchange using a fluid. In an embodiment, the foundation system includes at least one vertical pile member configured to install into a ground surface. A central insulated tube extends in a longitudinal direction within the vertical pile member. The central insulated tube is configured to transmit a geothermal heat exchange fluid therein. An input pipe and an output pipe are configured to transmit the geothermal heat exchange fluid through the vertical pile member and extend through the sidewall of the vertical pile member. A closed end, provided at the end of the pile member is configured to provide densified soil to increase heat transfer capability and efficiency in combination with the heat exchange limited by the central insulated tube. Other embodiments are also disclosed.

A thermal energy system adapted to be coupled to a building energy system which selectively provides heating and/or cooling to a building, the thermal energy system comprising a heat pump system having an output for a working fluid connected to a heating output of the thermal energy system, a first geothermal system in which a working fluid is, in use, circulated, a first switch assembly selectively connecting the first geothermal system to at least one of the heating output of the thermal energy system and an input for a working fluid of the heat pump system, a second geothermal system in which a working fluid is, in use, circulated, and a second switch assembly selectively connecting the second geothermal system to at least one of a cooling output of the thermal energy system and the input of the heat pump system.

A helical pile including a heat exchanger is described. The pile is formed from a lead section and one or more extension sections. The interior of the lead and extension sections are hollow and form a heat exchanger cavity. At the lower end of the lead section is a helical blade. Rotation of the lead section causes the helical blade to screw into the ground, thus pulling the lead section downward. Extension sections are added to the lead section and the pile is rotated until it is installed to a desired depth. The pile includes an inflow tube extending a predetermined distance into the heat exchanger cavity and an outflow port connected with the heat exchanger cavity. In operation, a heat carrying fluid is pumped into the inflow tube from a heat source or sink, for example, a heat pump for a building heating and cooling system. The fluid exits the tube at a point near the bottom of the heat exchanger cavity. The fluid flows upward through the heat exchange cavity and exchanges heat with the surrounding soil. The fluid flows out through the outflow port and back to the heat source or sink.

Thermal energy system, coupled to a building energy system, which selectively provides heating and/or cooling to a building. The thermal energy system includes a heat pump system, first and second geothermal systems, and first and second switch assemblies, and the first and second switch assemblies are selectively switchable to thermally interconnect the first and second geothermal systems to each other on a primary input side of the heat pump system or on a second output side of the heat pump system, and: a) the first and second switch assemblies are adapted to be switchable to provide a first operation mode which thermally connects the first geothermal system to the heating output and the second geothermal system to the cooling output, and the heat pump system being thermally unconnected to the first and second geothermal systems; or b) the first and second switch assemblies are adapted to be switchable to provide a first operation mode which thermally connects together the first and second geothermal systems via the heat pump system, and the heating output and cooling output being thermally unconnected to the first and second geothermal systems.

A helical pile including a heat exchanger is described. The pile is formed from a lead section and one or more extension sections. The interior of the lead and extension sections are hollow and form a heat exchanger cavity. At the lower end of the lead section is a helical blade. Rotation of the lead section causes the helical blade to screw into the ground, thus pulling the lead section downward. Extension sections are added to the lead section and the pile is rotated until it is installed to a desired depth. The pile includes an inflow tube extending a predetermined distance into the heat exchanger cavity and an outflow port connected with the heat exchanger cavity. In operation, a heat carrying fluid is pumped into the inflow tube from a heat source or sink, for example, a heat pump for a building heating and cooling system. The fluid exits the tube at a point near the bottom of the heat exchanger cavity. The fluid flows upward through the heat exchange cavity and exchanges heat with the surrounding soil. The fluid flows out through the outflow port and back to the heat source or sink.

A method and system for optimizing the operation of a geo-exchange system, by generating predictive models pertaining to energy demand and energy capacity for a particular building or district, based on data from sensors associated with components of a district geo-exchange system, historical and real-time operational data associated with district modules, including weather forecast data and current weather conditions.

A new system for and a method of deploying a heat exchanger pipe. A bore hole is drilled from an access ditch location to a terminal ditch location using a piloted drill head powered via an umbilical attached to the piloted drill head. A casing is attached to the piloted drill head and disposed about the umbilical into the bore hole from the access ditch location to the terminal ditch location. At the terminal ditch location, the piloted drill head is removed from the casing and the umbilical and a heat exchanger pipe is attached to the umbilical. The umbilical is withdrawn from within the casing deployed in the bore hole to pull the heat exchanger pipe into the casing. The casing is then withdrawn from the bore hole leaving the heat exchanger pipe in the bore hole.