A greenhouse, for cold weather climates, is configured with a gable that is offset toward the north wall and therefore the south extension of the roof, from the gable to the south wall is longer than the north extension. A greater amount of light can enter through this south extension and the inside surface of the north wall is configured with a reflective surface to allow light to be more uniformly distributed around the plants. The north wall may have no widows and may be thermally insulated to prevent the greenhouse from getting too cold during the night. A ground to air heat transfer (GAHT) system may be configured to produce a flow of greenhouse air under the greenhouse for heat transfer, to moderate the temperature of the greenhouse. A thermal medium may flow to a thermal reservoir for heat exchange with the conduits of the GAHT system.

Devices and methods for reflecting at least a portion of the heat output of a space heater are described. A supplementary reflector is positioned to reflect a portion of the heat generated by the space heater. The supplementary reflector can be angled relative to the vertical axis to direct reflected heat downwards, while also providing adjustable side panels that provide focus and further direction of the reflected heat.

A thermally enhanced heating system and a method for thermally enhancing a HVAC system are provided. The thermally enhanced heating system preferably includes an outdoor HVAC unit and an indoor HVAC unit. The indoor HVAC unit includes a first heat exchanger for transferring heat from a refrigerant, a second heat exchanger for transferring heat from a fuel source, and a third heat exchanger for transferring heat to the refrigerant. The outdoor HVAC unit includes an outdoor heat exchanger for transferring heat from an outdoor air to the refrigerant, a pump configured to circulate the refrigerant, and an ejector configured to combine the refrigerant from the outdoor heat exchanger and the third heat exchanger. Preferably the outdoor HVAC unit is operated to circulate the refrigerant through a first refrigerant circuit and a second refrigerant circuit, and combine refrigerant in the first refrigerant circuit and the second refrigerant circuit.

A heat recovery system includes a compressor, a solar panel, and a first heat exchanger and a second heat exchanger in fluid connection to form a closed circuit. The compressor is configured to facilitate fluid movement in the fluid circuit between the solar panel, the first heat exchanger and the second heat exchanger. The solar panel includes a plurality of solar cells connected in parallel, and each solar cell includes a plurality of metal tubes for fluid to pass through. A temperature sensor is mounted within each of the solar cells and configured to measure temperature inside the respective solar cell. Each solar cell is connected to the circuit via a respective pressure valve, and the status of the pressure valve is configured to depend on the measurement of the temperature sensor in the respective solar cell.

A hybrid photovoltaic and radiant heating and cooling device is provided, wherein the device comprises a photovoltaic panel; a radiant heating and cooling panel; a first heat-exchanging pipe in direct contact with a back surface of the photovoltaic panel; a second heat-exchanging pipe in direct contact with a back surface of the radiant heating and cooling panel; and a thermal storage tank fluidly connecting the first and the second heat-exchanging pipes, wherein the tank is arranged between the first and second heat-exchanging pipes.

A combination boiler provides heated water to a boiler loop and domestic hot water (DHW) to a domestic water loop. The combination boiler includes a primary heat exchanger (PHE) connected to the boiler loop and a burner to provide heat to the primary heat exchanger. A secondary heat exchanger (SHE) transfers heat energy from the boiler loop to the domestic water loop. A controller monitors a PHE inlet temperature and a DHW output temperature, obtains a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold, and detects a low temperature condition. A pre-heat operation is initiated responsive to the low temperature condition by circulating heated water from the PHE to the SHE. The burner is selectively fired at least in part according to an outlet temperature of the PHE.

A combination boiler provides heated water to a boiler loop and domestic hot water (DHW) to a domestic water loop. The combination boiler includes a primary heat exchanger (PHE) connected to the boiler loop and a burner to provide heat to the primary heat exchanger. A secondary heat exchanger (SHE) transfers heat energy from the boiler loop to the domestic water loop. A controller monitors a PHE inlet temperature and a DHW output temperature, obtains a pre-heat initialization temperature threshold and a pre-heat cancellation temperature threshold, and detects a low temperature condition. A pre-heat operation is initiated responsive to the low temperature condition by circulating heated water from the PHE to the SHE. The burner is selectively fired at least in part according to an outlet temperature of the PHE.

The present disclosure relates to a heating, ventilation, and/or air conditioning (HVAC) system including a heating coil and an actuation system configured to couple to the heating coil. The actuation system is configured to rotatably position the heating coil in a first orientation crosswise to an airflow path in a heating mode, and rotatably position the heating coil in a second orientation substantially removed from the airflow path in a cooling mode.

A bacteria abatement water heater abates bacterial growth and includes a fluid-isolated heat exchanger; a water heating container that heats water to a high water temperature that is greater than or equal to a kill temperature for bacteria; a hot water delivery conduit including a transitional cooling zone in thermal communication with the fluid-isolated heat exchanger and that provides bacteria-free water from the water heating container at a safe temperature.

A heat exchanger includes a burner configured to burn a combustible gas to produce heat, a heat exchanger configured to receive the heat from the burner, a flow sensor configured to measure a flow rate of a coolant passing through the heat exchanger; and a controller comprising processing circuitry. The processing circuitry receives flow data from the flow sensor and controls a firing rate of the burner based on a predetermined relationship between a differential temperature of coolant flowing through the heat exchanger and the coolant's flow rate.