Abstract: A heat exchanger fin is disclosed. The fin can include a fin portion and a collar portion defining a fin aperture that has a central axis passing therethrough. The collar portion can include a nesting end including a nesting portion and a receiving end that (i) is located apart from the nesting end in an axial direction and (ii) comprises one or more bends to form an overhang portion that defines a gap located radially inward of the overhang portion. The gap can be dimensioned to at least partially receive the nesting portion. The collar portion can also include a contact portion extending between the nesting end and the receiving end, and the contact portion can be configured to abut an outer surface of a tube when the tube is at least partially inserted into the fin aperture.

Abstract: The present disclosure provides a drain assembly for an AC furnace coil unit. The drain assembly includes a drain pan defining one or more drain channels extending longitudinally therealong, and an arcuate heat shield detachably coupled to the drain pan. The arcuate heat shield extends along a length of the drain pan. The arcuate heat shield is configured to define a cavity between an inner surface thereof and the drain pan, and distribute airflow, incident on an outer surface thereof, along longitudinal sides of the drain pan.

Abstract: Disclosed herein are air conditioning systems including a refrigerant line configured to transport a refrigerant; a compressor in fluid communication with the suction line; and a controller in communication with a sensor configured to measure a characteristic of the refrigerant line. The compressor can be configured to move the refrigerant through the refrigerant line, and the refrigerant can have a first temperature at the outlet of the compressor. The controller can be configured to receive sensor data from the sensor indicating a current value associated with the characteristic of the refrigerant line; determine, based at least partially on the sensor data, that the characteristic of the refrigerant line is above a predetermined threshold; and output instructions for the compressor to perform one or more corrective actions.

Abstract: The disclosed technology includes an air system including a first interlaced microchannel heat exchanger and a second interlaced microchannel heat exchanger. The air system can include a plurality of fluidly separated refrigerant circuits, and each of the refrigerant circuits can be configured to flow through the first interlaced microchannel heat exchanger and the second interlaced microchannel heat exchanger. The first interlaced microchannel heat exchanger can be located indoors, and the second interlaced microchannel heat exchanger can be located outdoors. Each of the refrigerant circuits can include its own compressor and expansion valve.

Abstract: A system for controlling air flow in an air handling unit having an air mover is provided. The system includes a first and a second sensing device, each receiving a first input indicative of electric power and a second input indicative of properties of air, respectively. The system further includes a processing unit to determine heat generated from a motor of the air mover based on the first input, determine density of air based on the heat generated from the motor based on the second input, and determine an actual air flow rate based on the density of the air, a speed of the motor, and dimensional characteristics of the air handling unit. Further, the speed of the motor is controlled when the actual air flow rate is different from a target air flow rate.

Abstract: Disclosed herein is a water heating system including a water heater having a tank, and a first temperature sensor disposed toward a top end of the tank to measure a first temperature and a second temperature sensor disposed toward a bottom end of the tank to measure a second temperature. The water heating system can further include a controller communicably coupled to the first temperature sensor and the second temperature sensor, where the controller determines an amount of heated water in the tank based on one or more algorithms and measurements made by the first and second temperature sensors.

Abstract: The disclosed technology includes a leak detection system for a fluid heating device, the leak detection system including: a structure configured to at least partially insert into a portion of a fluid heater; a fluid removing portion of or in contact with the structure, the fluid removing portion configured to transport water from the structure to at least one leak sensor; and the at least one leak sensor configured to detect the fluid transported from the structure by the fluid removing portion.

Abstract: A stamped bare wire metal heating element for heating fluid in a tankless electric fluid heating device may include a first electrically conductive portion extending linearly; a second electrically conductive portion extending linearly; and a third electrically conductive portion connecting the first electrically conductive portion to the second electrically conductive portion at a first end of the stamped bare wire metal heating element, wherein the stamped bare wire metal heating element is open between the first electrically conductive portion and the second electrically conductive portion at a second end of the stamped bare wire metal heating element.

Abstract: The disclosed technology includes a tankless liquid heater system for detecting buildup on a heating element, including: a chamber; at least one heating element to heat liquid in the chamber; at least one sensor to detect data associated with identifying buildup on the at least one heating element; and at least one device to: receive the data detected by the at least one sensor; determine, based on the data, an amount of the buildup on the at least one heating element; and adjust an operation of the at least one heating element based on the amount of the buildup on the at least one heating element.

Abstract: The disclosed technology includes a heat pump having a thermal energy storage (TES) material. The heat pump can include a first heat exchanger to exchange heat between ambient air and refrigerant, a second heat exchanger to exchange heat between the refrigerant and air supplied to a climate-controlled space, and a third heat exchanger to exchange heat between the TES material and the refrigerant in a first fluid path and the refrigerant in a second fluid path. The heat pump can include a first compressor to circulate refrigerant to the first, second, and third heat exchangers and a second compressor to circulate refrigerant to the second and third heat exchangers. The first compressor can facilitate heat exchange between the ambient air and the TES material and the second compressor can facilitate heat exchange between the TES material and the air supplied to the climate-controlled space.

Abstract: A water heater and a cover assembly for the water heater is provided. The water heater includes a mixing valve disposed in fluid communication with each of a hot water conduit and a cold water pipe, to regulate temperature of hot water received from the hot water conduit. The cold water pipe branches from a cold water conduit and extends along a longitudinal axis of the tank to connect with the mixing valve. The cover assembly is mounted on a tank of the water heater. The cover assembly includes a first cover to conceal the cold water pipe, and a second cover to conceal the mixing valve and the hot water conduit extending between the tank and the mixing valve. The second cover is removably coupled to the first cover via one or more coupling elements.

Abstract: A combination water heating, air conditioning refrigerant system is described. The combined system includes a plurality of independently adjustable electronic expansion valves. The expansion valves can independently modulate the delivery of high-temperature, high-pressure refrigerant to either a water heat exchanger or an outside condenser. A controller can receive input signals, including temperature signals from one or more temperature sensors that indicate the temperature at various locations of the system. The temperature signals include one or more of water temperature signals, ambient air temperature signals, or refrigerant super heat temperatures signals. In response to the input signals, the controller can output control signals to one or more of the plurality of electronic expansion valves.

Abstract: The present disclosure provides a louvered fin including a leading edge, a trailing edge, and a surface extending between the leading edge and the trailing edge. The surface defines a first set of holes along a first axis, a second set of holes along a second axis and offset from the first set of holes, and a third set of holes along a third axis and offset from the second set of holes. Each of the first axis, the second axis, and the third axis extends substantially parallel to a longitudinal axis of the fin. A first offset distance between the second and first set of holes is greater than a second offset distance between the third and second set of holes. The second and the third set of holes define a substantially obtuse trapezoidal matrix.

Abstract: The disclosed technology includes devices, systems, and methods for heat pump systems configured to operate in low ambient temperatures. The disclosed technology can include a heat pump water heater system having an evaporator, a first compressor configured to compress refrigerant to a first pressure, and a second compressor configured to compress the refrigerant to a second pressure. The second pressure can be greater than the first pressure. The heat pump water heater system can include a preheater configured to receive the refrigerant at the first pressure and heat water and a condenser configured to receive the refrigerant at the second pressure and heat water. The water can be passed through the preheater before being passed through the condenser.

Abstract: Disclosed herein are fluid chemistry systems comprising fluid chemistry manifolds. The fluid chemistry manifolds can comprise an inlet, two flow paths in fluid communication with the inlet, one or more probe apertures, and an outlet in fluid communication with the two flow paths. The one or more probe apertures can be configured to receive at least a portion of a corresponding fluid chemistry probe. The probe can be configured to detachably attach to the one or more probe apertures and fluidly communicate with the flow path. The probe can include one or more of a pH sensor, an oxidation reduction potential (ORP) sensor, and a total dissolved solids (TDS) sensor. The systems can also comprise an adjustable valve configured to selectively permit a predetermined amount of fluid flow through the at least one of the two flow paths.

Abstract: The disclosed technology includes an on-demand water heater which uses a heat pump to heat the fluid. The on-demand heat pump water heater can have a low fluid capacity heating chamber which has an inlet and an outlet, a heat pump for heating the fluid, and a controller to control the heat pump and maintain the temperature of the fluid at a predetermined temperature. The on-demand heat pump water heater can include one or more temperature sensors, flow sensors, fluid mixing valves, or supplemental heat sources.

Abstract: The disclosed technology includes an integrated system including a space conditioning system, a liquid heating system, and a controller. The space conditioning system can include a refrigerant circuit fluidly connecting a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, an expansion valve, and a reversing valve such that refrigerant can flow through the circuit. The liquid heating system can include a liquid heating device and a liquid circuit configured to direct liquid from the liquid heating device through the first heat exchanger. The controller can be in electrical communication with the space conditioning system and the liquid heating system. The controller can be configured to determine a demand of the space conditioning system and the liquid heating system, and in response, output instructions to a plurality of valves to direct the refrigerant through the refrigerant circuit and direct the liquid through the liquid circuit.

Abstract: A tube for a thermal transfer device can include at least one wall having an inner surface and an outer surface, where the inner surface forms a cavity. The inner surface can be non-cylindrical. The cavity can be configured to receive a fluid that flows continuously along a length of the at least one wall.

Abstract: A heating unit for heating fluid is described having at least one electrical resistance heating element on an outer surface of a tube. At least one indexed groove is provided around a surface of the tube allowing for at least one retention clip to hold the electrical resistance heating element. A heating chamber is also provided to enclose a portion of the tube and to provide a flow channel therebetween. The heating chamber includes an optical sensor to detect overheating of the at least one electrical resistance heating element. Fluid is heated by flowing over the surface of the at least one electrical resistance heating element and through the tube.