Low Noise Exhaust System

BACKGROUND

Technical Field

[0001]The present disclosure relates generally to exhaust systems, and more specifically, to a device and system for significantly reducing the indoor noise level of exhaust systems, such as kitchen and bathroom vents, while simplifying installation.

[0002]The Conventional exhaust systems typically utilize in-duct installation of the exhaust blower equipment inside the building, which results in significant noise transmission into the indoor space. Furthermore, the noise-generating blower unit is often directly coupled to the indoor ductwork and structure, leading to vibration transmission and associated noise generation. Current solutions often involve complex installation procedures. There is a need for an exhaust system that effectively reduces indoor noise through acoustic and vibrational decoupling, is easier to install, and provides maintenance advantages.

SUMMARY

[0003]The current disclosure of invention(s) is related to a device which can be assembled into, for example, a new or old kitchen and bathroom exhaust systems and other in-door household or industrial gas or water pumping equipment. The use of the current invention(s) to the abovementioned applications is mainly for the purpose of reducing the in-door noise level of the exhaust systems in question. The other advantage of utilizing the current invention(s) is that it provides easier installation procedure than that of the conventional exhaust system which is typically utilizing the in-duct installation of the exhaust blower equipment.

[0004]The present disclosure introduces a low noise exhaust system for use with household or industrial gas or water pumping equipment, such as kitchen or bathroom exhaust systems. The system includes a blower assembly mounted outside the building's barrier or enclosure surface (e.g., roof or wall) to relocate the primary noise source outdoors. The blower assembly is connected to the indoor exhaust pipe via a flex tube and an inlet pipe. A filter system is mounted inside the blower assembly's inlet end to absorb high-frequency acoustic energy and filter grease. The system utilizes multiple vibration isolators and an adhesive plate to decouple the blower assembly from the building structure, and is designed with various configurations (e.g., changes in pipe diameter and material composition) to create acoustic impedance mismatches throughout the system, thereby maximizing transmission loss and significantly reducing the indoor noise level. The outdoor mounting location, which is preferably lower than the indoor pipe connector, also facilitates grease drainage away from the indoor hood.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]The embodiments may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. These drawings are used to illustrate only typical embodiments of this invention, and are not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

[0006]FIG. 1 is a schematic diagram illustrating one exemplary embodiment of the low noise exhaust device.

[0007]FIG. 2 is a schematic diagram illustrating an application of the low noise exhaust device to a vertical range-top exhaust system.

[0008]FIG. 3 is a schematic diagram illustrating an application of the low noise exhaust device to a horizontal range-top exhaust system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009]The description that follows includes exemplary apparatus, methods, techniques, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.

[0010]With reference to FIG. 1, one exemplary embodiment of the invention(s) is a low noise exhaust device 20 which mainly includes or consists of a blower assembly 4, a flex tube 6, a vibration isolator 5, an adhesive plate 13 and a tail pipe 7 as depicted in FIG. 1.

[0011]The blower assembly 4 includes or consists of an inlet pipe 11, a filter system 10, another vibration isolator 14, a blower unit 12 and an exhaust tail pipe 7 with a flipper 8 at the end of the exhaust tail pipe 7. Exhaust tail pipe 7 is twisted by about 75° angle at the end with a small hole 8a at the twisting point of the exhaust tail pipe 7 as shown in FIG. 1. The adhesive plate 13 is provided to attach it to the irregular roof surface or outdoor wall of the kitchen (not shown) by means of, for example, the commercially available LIQUID NAIL brand or epoxy glue which can be applied with sufficient amount on the bottom side of adhesive plate 13 as well as the irregular roof or wall surfaces (both not shown) such that the current exemplary embodiment of the invention(s) including the blower assembly 4, the vibration isolator 5, the inlet pipe 11, the flex tube 6 and the tail pipe 7 are glued on the irregular roof or outdoor wall surface. Hold-down tape 15a and hold-down tape 15b may be used to hold down the low noise exhaust device or system 20 on the roof or the wall before the abovementioned glue becomes solidified. The vibration isolator 14 provides transmission loss between blower unit 12 and filter system 10.

[0012]Filter system 10 includes or consists of a section with coarse metallic filter (not shown) and a section of filter with fine opened-cell plastic foam or fiber glass (not shown). These filter materials, firstly, absorb relatively high frequency acoustic energy and reduce acoustical transmission from the blower unit 12 towards or in the upstream direction. Any substance condensed from the suspended particles in exhaust gas, such as the grease, is also, secondly, filtered by the filter system 10 prior to reaching the blower unit 12 and it keeps the blower unit 12 from being stained. The entire filter system 10 is designed to be easily disassembled for easy cleaning and replacement purposes.

[0013]It should be noted that the inner diameter of the inlet pipe 11 and the inner diameter of exhaust pipe 7 is different from the inner diameter of the housing of the blower assembly 4, that creates relatively low frequency transmission loss due to acoustic impedance mismatch between inlet pipe 11 and blower assembly 4 as well as between the exhaust pipe 7 and blower assembly 4. The blower assembly 4 is designed to be weather proof and easy disassembled for motor-repair or replacement purposes and it is optionally enclosed with relatively heavy sheet metal for outdoor noise suppression purpose.

[0014]The vibration isolator 14 is located between the blower unit 12 and the filter system 10 to provide transmission loss by reducing the transmission of vibration induced by the blower unit 12 towards the upstream components (filter system 10, inlet pipe 11, flex tube 6, and exhaust piping/hood).

[0019]Outdoor Mounting and Isolation: The entire low noise exhaust device 20, including the blower assembly 4, is designed to be installed outdoor on a barrier/enclosure surface, such as a roof or wall. This is a primary source of indoor noise reduction as the noise source is relocated outside.

[0020]The adhesive plate 13 and vibration isolator 5 are used for mounting. The vibration isolator 5 is connected around the blower assembly 4, downstream from the flex tube 6, the inlet pipe 11, and the filter system 10. The adhesive plate 13 is provided to attach the combined unit (vibration isolator 5 and blower assembly 4) to the irregular roof or outdoor wall surface (not shown) using commercially available high-strength adhesive (e.g., LIQUID NAIL brand or epoxy glue).

[0021]The combination of the vibration isolator 5 and the adhesive plate 13 increases the transmission loss of vibration from the blower assembly 4 to the building structure. Furthermore, the material used for the vibration isolator 5 is different from the material of the adhesive glue, which creates a further acoustic impedance mismatch between the vibration isolator 5 and the roof/wall surface, enhancing vibrational transmission loss. Hold-down tapes 15a and 15b may be used temporarily during glue solidification.

Applications of Current Invention(s) to Low Noise Exhaust System

[0022]FIG. 2 shows an application of the current invention(s) to an exemplary embodiment of a range-top exhaust system 30 where the exhaust system 30 draws exhaust gas 1v out of a roof, barrier, or enclosure surface 9v vertically through exhaust hood 2v, exhaust pipe 3v, and a pipe connecter 11v as depicted. The blower assembly 4 of the current invention(s) is installed outdoor on the rooftop at a location lower than the pipe connector 11v as shown in FIG. 2. At installations, the flex tube 6 is connected to the pipe connector 11v and the entire blower assembly 4 along with the vibration isolator 5 is glued on the roof surface 9v through its adhesive plate 13. Since the blower assembly 4 is installed at the level below the exhaust pipe connector 11v, any substance condensed from the suspended particles in the exhaust gas 1v, such as the grease, cannot flow back to the exhaust hood 2v and it keeps the exhaust hood 2v as well as the range top relatively clean. As explained in the previous sections, the adhesive plate 13 is designed to glue or adhere the combined unit of vibration isolator 5 and the blower assembly 4 on the irregular surface of roof 9v. The substantial changes in adjoining structures or pipe configurations (e.g., between exhaust pipe 3v and flex tube 6, and between flex tube 6 and inlet pipe 11) create increased acoustic impedance mismatch, which further increases transmission loss from the blower assembly 4 back to the hood 2v. If the pipe connector 11v is made with a different inner diameter than the exhaust pipe 3v, this further enhances the impedance mismatch.

[0023]Similarly, FIG. 3 shows another application of the current invention(s) to an exemplary embodiment of a range-top exhaust system 40 where the exhaust gas 1h is drawn out of the kitchen horizontally through a wall, barrier, or enclosure surface 9h rather than being drawn out of the kitchen vertically through roof 14h. This exemplary embodiment of the current invention(s) device is similarly installed at the location lower than the pipe connector 11h. The installation of the current invention(s) exemplary embodiment of the device to this horizontal exhaust system 40 is identical to that of the previous example of a vertical exhaust system 30 except that the combined unit of vibration isolator 5 and the blower assembly 4 is attached through the adhesive plate 13 to the wall 9h rather than the roof 14h. This horizontal exhaust system 40 includes an exhaust hood 2h, an exhaust pipe 3h, and a horizontal exhaust pipe 3ah.

[0033]While the embodiments are described with reference to various implementations and exploitations, it will be understood that these embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions, and improvements are possible.

[0034]Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.