The present disclosure generally relates to water heaters, and more particularly relates to systems methods for duct-free heat pump water heaters.
Heat pump water heaters are heat-exchangers that heat a volume of water using heat in the surrounding ambient air. As depicted in
After the heat is extracted from the ambient air to heat the refrigerant, the now cooled and humidified air is driven out of the chamber. Heat pumps equipped with a duct will drive the air through the ductwork and out of the house, for example. Duct-free heat pumps, on the other hand, drive the cool and humidified air into the immediate surroundings. Conventional duct-free heat pumps for water heaters, such as the one depicted in
Therefore, it would be desirable to mitigate and minimize the effects of a duct-free heat pump water heater on the temperature of the surrounding air.
The detailed description is set forth with respect to the accompanying drawings. The use of the same reference numerals may indicate similar or identical items. Various embodiments may utilize elements and/or components other than those illustrated in the drawings, and some elements and/or components may not be present in various embodiments. Elements and/or components in the figures are not necessarily drawn to scale.
This disclosure relates generally to duct-free heat pumps for water heaters, hereinafter referred to simply as “heat pumps” for simplicity. In some instances, the heat pump is configured to have a substantially downward air flow. For example, in certain embodiments, the heat pump includes an air inlet disposed above a plurality of air outlets distributed around a perimeter of the heat pump housing. By arranging the airflow vertically and using a plurality of air outlets distributed around the perimeter of the heat pump housing, the cool air generated by the heat pump may be diffused, rather than concentrated in a localized area. In some instances, the cool air may be diffused 360 degrees about the perimeter of the heat pump housing. This cool air is therefore discharged into a larger volume of the surroundings, reducing the cooling effect in any particular discrete volume of air. Furthermore, by diffusing the cool air, the volume of discharged cool air has a greater surface area contacting the relatively warm surrounding air, enabling swift temperature equilibration with the surroundings and a reduced cooling effect overall. More so, by diffusing the cool air, the air stream is less concentrated and therefore less noticeable by the user as it exits the water heater.
In some embodiments, a heat pump for a water heater is disclosed. The heat pump may include a housing having at least one air inlet and a plurality of air outlets distributed around a perimeter of the housing. In some instances, the at least one air inlet may be disposed about a top portion of the housing, and the plurality of air outlets may be disposed about a lower portion of the housing below the air inlet. In some embodiments, the heat pump may include a fan (or blower) positioned adjacent to the at least one air inlet so that the fan is configured to blow and/or pull air downward through the at least one air inlet and into the housing. In some instances, the fan may be positioned in a horizontal plane about the top of the housing adjacent the at least one air inlet such that the blades of the fan rotate in a substantially horizontal plane. The fan may be located anywhere about the housing so as to blow and/or pull air through the at least one inlet and out of the plurality of outlets.
The at least one air inlet may be in the form of one air inlet positioned along a top surface of the heat pump so that the air is blown downwards into the housing. In this manner, in some instances, the airflow through the heat pump housing may be substantially vertical in a downward direction. Any number of air inlets may be used herein. For example, the at least one air inlet may be in the form of a plurality of air inlets positioned around a perimeter of the housing. The at least one fan may be positioned inside the housing along an interior surface of the air inlet, or the fan may be positioned outside the housing along an exterior surface of the air inlet. In some embodiments, there are multiple air inlets, each with a single fan. In other embodiments, each air inlet has more than one fan. In still further embodiments, a single fan may be configured to blow air through a plurality of air inlets. The at least one air inlet may have any suitable size, shape, or configuration. For example, the at least one inlet may be a circular shape, square shape, or another shape. Any combination of air inlets and fans may be used depending on the needs of the application.
In some embodiments, the plurality of air outlets are positioned on a lower edge of the perimeter of the housing. The plurality of air outlets may be located anywhere about the housing. In some instances, the plurality of air outlets may collectively form a single large outlet about the perimeter of the housing (e.g., a single slot or the like about the housing). The plurality of air outlets may include a suitable number of air outlets positioned to facilitate effective dissipation of the cool air generated by the heat pump. For example, the plurality of air outlets may include two air outlets positioned on opposite sides of the heat pump housing so that air is dissipated in two directions. The plurality of air outlets may include four air outlets positioned equidistantly around the perimeter of the heat pump housing so that air is dissipated in four directions. The plurality of air outlets may include more than four air outlets, such as 5, 10, 15, 20, or more air outlets, or any number of air outlets in between, positioned equidistantly from each other around the perimeter of the heat pump housing. The plurality of air outlets may be arranged in one row, two rows, three rows, or more rows, or the plurality of air outlets may be arranged in a pattern around the perimeter of the heat pump housing. Any number of air outlets in any combination may be utilized to achieve effective dissipation of cool air as described herein. The plurality of air outlets may have any suitable size, shape, or configuration. For example, the plurality of air outlets may be a circular shape, square shape, or another shape.
In some embodiments, the heat pump may include an evaporator positioned adjacent to the at least one air inlet. The evaporator may include one or more evaporator coils such that air from the at least one fan passes over the one or more evaporator coils. The heat pump may include one air inlet so that the evaporator includes one evaporator coil positioned adjacent to the air inlet. The heat pump may include two or more air inlets so that the evaporator includes one evaporator coil for each air inlet. A particular evaporator coil may be suitable for positioning adjacent to two or more air inlets depending on the size and positioning of the air inlets. For example, the heat pump may include four air inlets in a top surface of the heat pump housing, and the evaporator may include one evaporator coil approximately equal in size to all four air inlets so that the evaporator coil is effectively warmed by the air blowing through the air inlets. Any number of evaporator coils that are effectively warmed by the air inlets in a particular heat pump housing may be used depending on the needs of the application.
In some embodiments, the heat pump may include a diffuser positioned adjacent to the evaporator effective to redirect air passing over the one or more evaporator coils to each of the plurality of air outlets. In some instances, the diffuser is disposed directly beneath the evaporator. The positioning and shape of the diffuser may depend on the number and positioning of air inlets, the number and positioning of evaporator coils, and/or the number and positioning of air outlets. For example, in an embodiment in which the heat pump includes one air inlet disposed in a top surface of the housing and an evaporator with one evaporator coil disposed adjacent to the air inlet in the top surface of the housing, the diffuser may have a dome or cone shape. The dome or cone shaped diffuser may be positioned such that the air passing over the evaporator coil is redirected from a downward direction to a radially-outward direction and through each of the plurality of air outlets. In embodiments in which multiple air inlets, a single diffuser may be effective to redirect incoming air to the plurality of air outlets. In other embodiments, a diffuser may be present for each air inlet to more effectively redirect air blown in through that particular air inlet.
In some embodiments, the heat pump includes a compressor positioned adjacent to the diffuser. The evaporator coil and the compressor may be fluidly connected and form part of a vapor-compression refrigeration system, which also includes, amongst other components, a condenser (e.g., condenser coil) and expansion valve. As described previously, the fluid in the evaporator coil is warmed by the air blown into the housing by the one or more fans. However, the fluid is rarely warmed by the air to a temperature sufficient to effectively heat the water in a water heater. By passing this fluid through a compressor, the fluid in the compressor is pressurized, thereby heating the fluid further and vaporizing it. Furthermore, when the heat pump is installed on a water heater, the heated fluid in the evaporator coils and compressor is used to heat water in the water heater, resulting in a re-condensed, cooled fluid re-entering the evaporator coils after warming the water. This cooled fluid, as well as the newly cooled air blowing across the evaporator coils can result in condensation that may drip onto the compressor and inadvertently cool the newly heated fluid. Thus, in some embodiments, the compressor is positioned adjacent to (e.g., directly beneath) the diffuser so that condensation may collect on the diffuser rather than contact the compressor. In some instances, the diffuser may substantially surround the compressor.
In some embodiments, the diffuser may include a lip around a perimeter of the diffuser configured to collect condensation. The diffuser may also include a drain pipe connected to the lip configured to direct collected condensation out of the heat pump. As described above, condensation may build up and fall from the evaporator as a result of the fluid within the coils cooling during the water heating process. This cooled fluid, as well as the newly cooled air blowing across the evaporator coils, may result in condensation that can drip on the surface of the diffuser. Depending on the geometry of the heat pump, this condensation may be captured by the lip and safely removed from the heat pump using the drain pipe. In some embodiments, the diffuser has a perimeter that is touching or is joined to the heat pump housing. In this way, any condensation that may form on the inner surface of the heat pump housing may fall onto the lip of the diffuser.
In embodiments in which the at least one fan is disposed within the heat pump housing, it is possible for condensation to form on the fan itself. As a result of the fan's rotation during use, this condensation may be expelled radially and may collect on the inner surface of the heat pump housing. Therefore, in embodiments in which the at least one fan is disposed within the heat pump housing, the lip on the diffuser may be responsible for collecting condensation deposited on the heat pump housing by the fan. In other embodiments, the evaporator and diffuser may be disposed within a secondary housing within the heat pump housing, thereby isolating the components primarily responsible for heat exchange and preventing or mitigating the deposition of condensate by a fan disposed within the heat pump housing.
In some embodiments, the diffuser includes a plurality of fins, which are configured to redirect air passing over the diffuser to each of the plurality of air outlets. In embodiments in which there are multiple air outlets around the perimeter of the housing, there may not be a need for fins because the surface area of air outlets is high. However, in embodiments in which there are fewer air outlets, such as 2, 3, 4, 5, 10, or 15 air outlets (depending on the shape and size of each air outlet), the relative surface area of air outlets to the heat pump housing surface immediately surrounding the plurality of air outlets may be low, such as 0.5 or less. In these embodiments, it may be advantageous to incorporate fins on the surface of the diffuser that redirect or “funnel” air more directly to each of the plurality of air outlets. For example, in an embodiment in which there are four air outlets positioned equidistantly from each other around the circumference of a round heat pump housing, the diffuser may include an “X”-shaped recessed defined by a number of fins that redirect the downward-flowing air from the air inlet directly to each of the four air outlets.
In some embodiments, the heat pump includes insulation disposed within the housing. Depending on the conditions of the heat pump and the environment, it is possible for condensation to form on the housing walls. The insulation may be disposed around the perimeter of the housing so as to insulate the housing walls from temperature fluctuations created by heat pump operation. By including insulation within the housing, any condensation that forms within the heat pump is more likely to form on the evaporator and/or on the diffuser. The insulation may have a constant thickness around the perimeter of the heat pump housing. The insulation may be in the form of a cone or wedge having a greater thickness, for example, immediately adjacent to the at least one fan and the evaporator, thereby creating additional flow control for air entering the heat pump housing. The insulation may be discontinuous around the perimeter of the housing to permit space for, for example, additional air inlets/outlets, connection points for accessories, and the like. In some embodiments, the insulation dampens noise generated by the heat pump, further improving the user experience.
In some embodiments, the evaporator coil and compressor include a refrigerant. For example, the refrigerant may be propane, isobutene, ammonia, hydrofluoroolefin, carbon dioxide, difluoromethane, 1,1,1,2-tetrafluoroethane, pentafluoroethane, mixtures thereof, or another suitable refrigerant. Any suitable refrigerant may be used in the vapor-compression refrigeration system.
Water heaters equipped with a heat pump typically include the heat pump on top of the water tank with a condenser coil extending into the water tank. In the vapor-compression refrigeration system, the condenser coil is fluidly connected to the compressor and the evaporator so that a fluidic circuit is formed in which a refrigerant is heated and vaporized in the evaporator coils and the compressor before heating the water in the water tank and condensing in the condenser coil. In some embodiments, the water tank includes a water inlet for accepting water to be heated and a water outlet for discharging heated water. In some instances, the water heater includes a water tank having a fluid chamber and a condenser coil. The water heater may include a heat pump as described herein, which heat pump includes a compressor and one or more evaporator coils. In some embodiments, the compressor, evaporator coil, and condenser coils are fluidly connected to form a vapor-compression refrigeration system.
In some embodiments, the water tank and the heat pump disposed thereon may have the same circumferential shape. For example, water heaters often have a cylindrical shape, so both the water tank and the heat pump disposed thereon may have a cylindrical shape with the same diameter. In embodiments in which the heat pump is cylindrical, the diffuser may have a circular circumferential shape to complement the cylindrically shaped heat pump housing. In other embodiments, the heat pump and water tank may have different circumferential shapes, such as a cylindrical water tank and a rectilinear heat pump (approximating a cube, for example). Water heaters are also commonly sold commercially having a rectangular circumferential shape, so the water tank and heat pump of the present disclosure may have a rectangular circumferential shape. Since the heat pump couples to the water tank using, for example, one or more gaskets, mechanical joining hardware, and the like, any combination of shapes for the heat pump and water tank may be utilized depending on the needs of the application and desired aesthetics.
In some embodiments, the water heater includes one or more supplemental heating elements. Typical water heaters that do not utilize a heat pump rely on electrical heating elements and/or gas burners as the primary or sole source of heat. Heat pumps provide significant improvements in energy efficiency, but heat pumps may not always be capable of meeting the needs of a particular user or household. Thus, a heat pump-equipped water heater may have one or more supplemental heating elements that more quickly heat the water in the water tank at the cost of reduced energy efficiency. The supplemental heating elements may be in the form of, for example, electrical heating elements such as resistive coils. In other embodiments, the supplemental heating elements may be in the form of, for example, gas burners.
Depending on the components and construction of the heat pump, conventional heat pumps generate noise usually most attributable to the fan. In some embodiments, the fan size and placement; diffuser size, placement, and shape; air inlet size and shape; and the number of air outlets and air outlet shape and placement may be tuned so as to minimize the amount of noise generated by the heat pump described herein.
Turning now to the drawings,
Air passes through the air inlet 104, across the evaporator coils 108, and exits the heat pump through the air outlet 106. Fluid, such as a refrigerant, is heated in the evaporator coils 108 and compressed by the compressor 110. Fluid compressed by the compressor 110 enters a condenser coil 112 disposed within the water tank 114, which may have one or more additional heating elements 116. The water heater 102 is also equipped with a water inlet 118 and a water outlet 120. As depicted in
Turning now to
In the embodiment depicted in
In some instances, the fan 308 may be positioned adjacent to the air inlet 306. In certain embodiments, the fan 308 may be substantially exterior to the inside volume of the housing 305, i.e., on the outside of the heat pump 302 and configured to “push” air into the inside of the housing 305. In other instances, the fan 308 may be positioned substantially inside the housing 305, i.e., on the inside of the heat pump 305 and configured to “pull” air into the inside of the housing 305. The fan 308 may be disposed within the surface of the housing 305 itself, substantially in-line with the housing 305 so that the fan is partially inside and partially outside the housing 305. In some instances, the fan 308 may include a number of blades 309 positioned about the top (either inside and/or outside of the housing 305) in a substantially horizontal plane. That is, instead of being positioned vertically, the fan 308 is positioned horizontally to pull and/or push air substantially downward into the inlet 306 and out of the outlets 318. In embodiments with a plurality of air inlets 306, there may be one fan for each air inlet 306, or there may be one fan configured to push and/or pull air through more than one air inlet 306. For example, an embodiment in which a plurality of air inlets 306 are disposed within the top surface 307 of the housing 305 may include only one fan large enough to push and/or pull air through all of the air inlets 306. In embodiments in which the air inlets 306 are all disposed in the top surface 307 of the housing 305, the air flow may be directed substantially downward into the housing 305. In other embodiments in which one or more air inlet 306 are disposed on a side surface 317 of the housing 305, the air flow through the housing 305 may be in a direction other than substantially downward and still achieve the air dispersion effect as described above. For example, four air inlets 306 distributed equidistantly around a perimeter of the housing 305 may each be configured to direct air into the housing 305, and the air flow may therefore be governed by the position of the air outlets 318 instead. The air inputs 306 and corresponding fans 308 may be configured to direct air towards a center point within the housing 305, or they may be configured to direct air at a point other than the center, such as a plurality of fans configured to create a “vortex” of air within the housing 305 by directing the air along the inner housing wall within the housing 305.
As depicted in
The diffuser 312 may include a lip 311 and drain pipe 313 configured to collect condensation 320 from the cooled air and direct the condensation 320 that collects on the diffuser 312 out of the heat pump 302. For example, condensation 320 may drip from the coils of the evaporator 310 onto the diffuser 312 via gravity. The condensation 320 may trickle down the diffuser 312 to the lip 311, where the condensation 320 may collect. The lip 311 may include one or more surfaces or slopes configured to direct the condensation 320 to the drain pipe 313, where the condensation 320 may be directed outside of the heat pump 302 via of the drain pipe 313. Depending on the number of air inlets 306 and fans 308, there may be one or more evaporators 310, and each evaporator 310 may be formed from one or more evaporator coils. There may be at least one evaporator coil disposed next to each air inlet. In embodiments in which multiple air inlets, multiple fans, and/or multiple evaporator coils are present, additional diffusers may be present to control the flow of air through the housing and to collect the condensation from the cooled air passing over the evaporator coils.
As depicted in
Other suitable shapes for the diffuser may be used, such as a cone, a pyramid, a dome, an inverted bowl, or an irregular shape such as a star depending on the number and position of air outlets. In this manner, the diffuser may be any suitable size, shape, or configuration that is capable of directing the air flow from the inlets to the outlets, as well as collecting condensation from the evaporator.
In certain embodiments, the compressor 314 may be partially or wholly disposed beneath the diffuser 312. The compressor 314 is fluidly connected to evaporator 310 and condenser coil 316, which extends into or adjacent and wraps around the water tank 304, as depicted in
Air passed through the air inlet 306 passes over the diffuser 312 and is diverted out of the plurality of air outlets 318.
Condensation from the evaporator 506 may drip from the coils of the evaporator 506 onto the diffuser 508 via gravity. The condensation may trickle down the outer dome surface of diffuser 508 to a lip 515, where the condensation may collect. The lip 515 may include one or more surfaces or slopes configured to direct the condensation to a drain or the like, where the condensation may be directed outside of the heat pump 502.
In the embodiment depicted in
Modifications and variations of the methods and devices described herein will be obvious to those skilled in the art from the foregoing detailed description. Such modifications and variations are intended to come within the scope of the appended claims. It should be apparent that the foregoing relates only to certain embodiments of the present application and that numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the disclosure.
Although specific embodiments of the disclosure have been described, numerous other modifications and alternative embodiments are within the scope of the disclosure. For example, any of the functionality described with respect to a particular device or component may be performed by another device or component. Further, while specific device characteristics have been described, embodiments of the disclosure may relate to numerous other device characteristics. Further, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that the disclosure is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as illustrative forms of implementing the embodiments. Conditional language, such as, among others, “can,” “could,” “might,” or “may” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments could include, while other embodiments may not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.
This application claims priority to U.S. Provisional Application No. 63/483,372, filed Feb. 6, 2023, which is incorporated herein by reference.
Number | Date | Country | |
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63483372 | Feb 2023 | US |