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 method, system, apparatus, and/or device for preheating air for a rooftop air handling unit (RTU). The method, system, apparatus, and/or device may include a barrier system configured to surround the RTU. The barrier system may include a structure to provide a frame for the barrier system, a first barrier configured to connect to a first side of the structure, and a collector configured to connect to a second side of the structure. The method, system, apparatus, and/or device may include a duct configured to connect between the collector and a chamber. The method, system, apparatus, and/or device may include a chamber configured to connect to an air intake hood of the RTU. The chamber may include a first opening to receive air stored in the cavity, a second opening to receive external air, and a diverter configured to switch between a first position and a second position.

A water tank management system that connects either to a hot water tank directly or to an electric panel connected to the tank. The system comprises at least two temperature sensors, each of which is attached on the surface of the hot water tank near respective heating elements. The system comprises a control box which includes a solid-state relay that modulates the flow of electrical power to the heating elements in order to lower the energy used by the tank. The modulation is controlled by a program stored in a memory in the control box or communicated to the control box via an external controller. The system optionally comprises a third temperature sensor placed outdoors to measure the ambient outdoor temperature. With this feature, the system can activate a program to reduce energy consumption when the outdoor ambient temperature is outside a critical temperature range.

A method of protecting a single-stage furnace in a multi-zone system includes monitoring a temperature of each zone of a plurality of zones, determining if the temperature of at least one zone of the plurality of zones is less than a threshold temperature, powering on the HVAC system to satisfy a heating demand of the zone having a temperature less than the threshold temperature, monitoring an outlet temperature of the single-stage furnace, determining if the outlet temperature is greater than an outlet temperature threshold, and responsive to a determination that the outlet temperature is greater than the outlet temperature threshold, modulating a gas valve to reduce a flow of gas to the single-stage furnace.

Various implementations include a water heater system. The system includes a variable speed pump. The variable speed pump has having an inlet and an outlet. The system includes a heat exchanger, having an inlet and an outlet. The heat exchanger outlet is fluidically connected to the variable speed pump inlet. The system includes an output temperature sensor disposed downstream of the heat exchanger outlet. The system includes a controller configured to receive a first temperature reading from the output temperature sensor. The controller is configured to control operation of the variable speed pump to adjust an output flow rate in response to the first temperature reading. The controller is further configured to receive a second temperature reading from a recovery temperature sensor on a storage tank. The controller is configured to turn off the variable speed pump upon a determination that the second temperature reading has reached a maximum temperature.

Controlling heating and cooling in a conditioned space utilizes a fluid circulating in a thermally conductive structure in fluid connection with a hydronic-to-air heat exchanger and a ground heat exchanger. Air is moved past the hydronic-to-air heat exchanger, the air having fresh air supply and stale air exhaust. Sensors located throughout the conditioned space send data to a controller. User input to the controller sets the desired set point temperature and humidity. Based upon the set point temperature and humidity and sensor data, the controller sends signals to various devices to manipulate the flow of the fluid and the air in order to achieve the desired set point temperature and humidity in the conditioned space. The temperature of the fluid is kept less than the dew point at the hydronic-to-air heat exchanger and the temperature of the fluid is kept greater than the dew point at the thermally conductive structure.

A coaxial gas valve assembly includes a gas inlet, a gas outlet, a valve tube, and a shaft member. A main valve is movable between a closed position and an open position (broadly, openable and closable). A main spring is positioned to resiliently bias the main valve in its closed position. A redundant valve is movable between a closed position and an open position (broadly, openable and closable). A redundant spring is positioned to resiliently bias the redundant valve in its closed position. A solenoid coil is positioned to electromagnetically move the shaft member within the valve tube. A balance diaphragm is connected to the valve tube. A gas path through at least the valve tube allows gas flow from a first side of the balance diaphragm to a second side of the balance diaphragm to reduce a pressure difference between the first and second sides of the balance diaphragm.

An air heating apparatus according to the present disclosure includes an expansion tank that stores water, a water heater that receives heat from a combustion gas generated by a combustion reaction and heats the water, a heating heat exchanger that receives the water heated by the water heater and exchanges the heat with air to be discharged for heating, a fan that delivers the air to the heating heat exchanger, and a steam supply flow path that supplies steam in the expansion tank to the fan.

The present application provides apparatus (15) for connection to an HVAC-R system during maintenance or commissioning. The apparatus includes a plurality of ports (16, 17, 18) for fluid connection to the HVAC-R system and to maintenance apparatus, for example a refrigerant tank, a refrigerant recovery unit and/or a vacuum pump. The apparatus also includes a plurality of fluid connections (20) between the plurality of ports, each of the plurality of fluid connections having an electrically actuatable valve (21) to open and close the fluid connection. The apparatus also includes a control unit configured to control each of the electrically actuatable valves to configure the plurality of fluid connections.

A control device causes an air conditioning apparatus to execute a temperature adjustment operation of causing a first temperature to approach a first target temperature at a target time point and causing a second temperature to approach a second target temperature at the target time point. The first temperature is a surface temperature of a partition portion including at least one of a floor, a wall, and a ceiling facing a target space. The second temperature is an indoor temperature of the target space.