The present invention relates to a heat recovery device for use with a clothes dryer.
Electric and gas heated clothes dryers have become common household appliances during the past several decades for drying wet clothes inside a building, such as a house. As part of the typical clothes drying process, the clothes dryer produces hot air. The hot air flows through the wet clothes and is then exhaust to the exterior of the house by way of an exhaust vent. The practice of venting this hot exhaust air outside is particularly inefficient and results in wasted energy, which may result in increased operating costs, especially in recent years with the rapid rise in energy costs for homeowners. There are several problems, however, associated with simply venting the hot exhaust air from the clothes dryer directly back into the interior of the house which is why the conventional practice is to vent the exhaust air to the exterior of the house. For example, the hot exhaust air from the dryer typically contains a certain amount of moisture and lint picked up from the clothes being dried. As a result, it is undesirable to re-circulate the hot exhaust air into the interior of the house or even back into the dryer.
What is needed, therefore, is a device and method for recovering at least some of the driest hot air that would otherwise be exhausted to the exterior of the house and redirecting that hot air either back into the house or even the clothes dryer.
A heat recovery device for use on a clothes dryer includes a body having a main passageway with a central axis. The body has a first end and a second end and a dryer exhaust coupling proximate to the first end. The first end has a main flow inlet and the second end has a main flow outlet. The heat recovery device also includes a return air conduit coupled to the body. The return air conduit has a return air inlet and a return air outlet. The return air inlet is disposed within the main passageway and facing the main flow inlet. The dryer exhaust coupling is configured to be removably coupled to a dryer exhaust outlet of a clothes dryer such that the exhaust air discharged from the clothes dryer flows into the main flow inlet. The return air inlet is configured to receive a portion of the exhaust air discharged from the clothes dryer and discharge that portion through the return air outlet and a remainder of the exhaust air being discharged through the main flow outlet.
In one embodiment, when the heat recovery device is coupled to the dryer exhaust outlet, the central axis is substantially horizontal. In this embodiment, the return air outlet is configured to discharge the portion of the exhaust air from the clothes dryer in a direction substantially perpendicular to the central axis.
The return air inlet has a cross-section that is one of circular, semi-circular, elliptical, rectangular, square, or triangular.
In one embodiment, the return air inlet is disposed in an upper half of the main passageway.
In another embodiment, a heat recovery device for use on a clothes dryer, includes a body having a main passageway with a central axis. The body has a first end and a second end and a dryer exhaust coupling proximate to the first end. The first end has a main flow inlet and the second end has a main flow outlet. The heat recovery device also includes a return air conduit integrally formed to the body. The return air conduit has a return air inlet and a return air outlet. The return air inlet is disposed within the main passageway and faces the main flow inlet and the return air outlet is disposed outside the main passageway. The body and the return air conduit are comprised of a first half and a second half separable from each other along a plane extending through the central axis. The dryer exhaust coupling is configured to be removably coupled to a dryer exhaust outlet of a clothes dryer such that the exhaust air discharged from the clothes dryer flows into the main flow inlet. The return air inlet is configured to receive a portion of the exhaust air discharged from the clothes dryer and discharge that portion through the return air outlet and a remainder of the exhaust air is discharged through the main flow outlet. In one embodiment, a portion of the return air conduit external to the body has a T-shaped profile. When the heat recovery device is coupled to the dryer exhaust outlet, the central axis may be substantially horizontal. In that configuration, the return air outlet is configured to discharge the portion of the exhaust air from the clothes dryer in a direction substantially perpendicular to the central axis.
In one embodiment, the heat recovery device further includes one connector affixed to the body and one connector affixed to the return air conduit. Each connector is configured to couple together the first half and the second half.
In another embodiment, the return air conduit includes a cover with openings and the cover is coupled to the return air outlet. The cover may be slideably removable from the return air outlet and the openings may be elongated slots. The return air conduit may include openings on at least one side of the return air conduit. The return air inlet may have a semi-circular cross-section and the return air inlet is disposed in an upper half of the main passageway.
Other features of the heat recovery device are contemplated and described and claimed below.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more exemplary embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the embodiments of the invention.
The invention is intended to return heat, in the form of hot air, that is normally exhausted from a conventional clothes dryer to the exterior of a building, such as a house, and into the environment. According to one aspect of the invention, at least some of the hot air may be returned to the interior of the house, such as into the room where the clothes dryer is located, to heat at least part of the interior of the house. According to another aspect of the invention, at least some of the hot air may be returned back into the clothes dryer to enhance the drying efficiency of the clothes dryer. According to one aspect of the invention, little or none of the moisture and lint which may be entrained in the exhausted hot air from the clothes dryer is returned to the interior of the house or the clothes dryer.
With reference to
Various embodiments of heat recovery devices are shown in
The heat recovery device 20 is further illustrated in
With specific reference to
As shown in
The return air inlet 52 of the heat recovery device 20 in
In the embodiment of the heat recovery device 20 shown in
Different shapes and configurations of the return air inlet 52 of the return air conduit 50 would be apparent to one skilled in the art in order to alter the amount of warm air recovered. As such, the shapes and configurations are not limited to the shapes and configurations disclosed herein. In one embodiment shown in
In another embodiment shown in
In yet another embodiment shown in
Another embodiment of a heat recovery device 90 is shown in
With specific reference to
In an exemplary embodiment, the heat recovery device 90 may be constructed of two, separate halves 120, 122, which are held together by three connectors 124, two on the return air conduit 104 (
Each embodiment of the heat recovery devices 20, 90 discussed above includes a main passageway 42, 94, which has a central axis. Advantageously, in practice, the heat recovery devices 20, 90 will be coupled to the clothes dryer 12 such that the central axes of the main passageways 42, 94 are substantially horizontal and each of the return air outlets 54, 108 discharge return air substantially perpendicular to the central axis in a substantially vertical direction.
As mentioned above, the position of the return air inlet in the main passageway is likely to influence the amount of moisture in the returned hot air being discharged into the laundry room. That is, the return air inlet may be positioned to collected drier air or positioned to collect moister air. To evaluate the position of the return air inlet on the amount of moist in the returned hot air, the inventor conducted five tests. The five tests were conducted to evaluate how the temperature and humidity inside a laundry room containing a conventional, electric residential clothes dryer changed under varying venting configurations. The five tests were conducted in a laundry room measuring 5 feet by 6 feet with the laundry room door closed. Each test began with removing five beach towels from conventional, residential clothes washing machine after completing a normal wash cycle and placing them into the clothes dryer. The dryer was run for 30 minutes on the high heat setting. A temperate and humidity monitor made by ACU RITEā¢ sitting directly on the top center of the dryer was used to measure temperature and humidity immediately before and immediately after the drying cycle. None of the dryer exhaust was diverted back into the dryer during any of the five tests.
In Test No. 1, the dryer exhaust was vented directly to the outside like a typical clothes dryer is usually set-up and operated as schematically illustrated in
In Test No. 2, all of the dryer exhaust was vented directly into the laundry room as schematically illustrated in
In Test No. 3, the heat recovery device 20 similar to the one shown in
In Test No. 4, the heat recovery device 20 was connected to the clothes dryer in the same manner as in Test 3, but the return air conduit 50 was positioned such that the centerline of the return air inlet 52 was concentric with the centerline of the main passageway 42 of the body 40 of the heat recovery device 20 as illustrated in
In Test No. 5, the heat recovery device 20 was connected to the clothes dryer in the same manner as in Test 3, but the return air conduit 50 was positioned in the most vertically downward position in the main passageway 42 of the body 40 of the heat recovery device 20 as illustrated in
The table below summarizes the data that the temperate and humidity monitor collected during the five tests.
When looking at the data from Test Nos. 3-5, Test No. 3 yielded the greatest temperature gain, a rise of 7 degrees, and the lowest increase in humidity, a rise of 4 percentage points. Test No. 5 yielded the highest increase in humidity, 16 percentage points.
While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the inventor to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Thus, the various features of the invention may be used alone or in any combination depending on the needs and preferences of the user.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/715,988, filed Aug. 8, 2018 (pending) and U.S. Provisional Patent Application Ser. No. 62/728,205, filed Sep. 7, 2018 (pending), the disclosures of which are incorporated by reference herein in their entirety.
Number | Date | Country | |
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62728205 | Sep 2018 | US | |
62715988 | Aug 2018 | US |