The present disclosure relates generally to HVAC systems and, more particularly, to an HVAC system including a noise-reducing feature.
HVAC systems are often used for climate control of, e.g., internal cabin areas of an automobile. HVAC systems are typically configured with an HVAC unit having at least one heat exchanger disposed in a housing and, in some instances, an HVAC distribution system operatively connected to the HVAC unit. The HVAC system further includes one or more air flow paths for allowing air to flow, for example, to, from, and/or within the HVAC unit and the HVAC distribution system. Additionally, the HVAC system includes one or more doors operatively associated with the air flow path for controlling the amount of air flowing to, through, and/or from the HVAC unit and/or the HVAC distribution system. In instances where one of the doors is in a partially open position, substantially laminar high speed flow of the air travels through a gap formed in the air flow path between the door and the housing wall. In some instances, this high speed laminar air flow generates undesirable noises (e.g., whistles or hisses) in the HVAC.
An HVAC system including a noise-reducing feature is disclosed herein. The HVAC system includes a housing including at least one wall, an air flow path defined at least partially by the wall(s), and a door disposed in the air flow path, where the door is configured to i) block a flow of air through the air flow path when the door is in at least one closed position, and ii) allow the flow of air through the air flow path when the door is in a position other than the at least one closed position. A gap is formed between the door and the wall(s) when the door is in the position other than the at least one closed position. The HVAC system further includes a noise-reducing feature configured to break up, into several smaller structures, an air flow structure formed when air flowing through the gap contacts an edge of the door, thereby reducing air vibration in the gap and reducing noise of the HVAC during operation thereof.
Features and advantages of embodiments of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to the same or similar, though perhaps not identical, components. For the sake of brevity, reference numerals or features having a previously described function may or may not be described in connection with other drawings in which they appear.
Embodiment(s) of the HVAC system, as disclosed herein, include a noise-reducing feature configured to reduce audible noise generated by air flow through a gap defined in an air flow path between a door and a housing wall of the HVAC system. The noise-reducing feature advantageously reduces audible noise (such as, e.g., a whistle, a hiss, or the like) by as much as, for example, 10 decibels (dB). The noise-reducing feature is not only advantageously easy to incorporate into the HVAC system, but also does not substantially interfere with normal operations of the HVAC system, including, for example, functionalities of the door or other internal HVAC parts.
Referring now to the drawings,
The HVAC system 10, 10′ further includes a door 20, 20′ disposed in the air flow path 18. The door 20, 20′ could be any door used in the HVAC system 10, 10′, non-limiting examples of which include an air inlet door, a blend door, an air distribution door, air direction doors (such as, e.g., a door that directs air to the internal cabin of the motor vehicle or a door that directs air to defrosting/defogging systems), or the like, or combinations thereof. The door 20, 20′ is generally configured to block a flow of air through the air flow path 18 when the door 20, 20′ is in at least one closed position. For example, in instances where the door 20, 20′ is an air inlet door, the door 20, 20′ may have a single closed position; namely to prevent air from flowing into the HVAC system 10. In instances where the door 20, 20′ is an air distribution door, the door 20, 20′ may have more than one closed position. For example, the door 20, 20′ may be designed to close more than one air flow path (e.g., to distribute air between a defrost system, a ventilation system, and a passenger compartment of a vehicle). As used herein, the term “closed position” refers to a position of a door disposed in the air flow path 18 when an end 22 of the door 20, 20′ abuts the housing wall 14, thereby substantially restricting or even eliminating flow of air through the air flow path 18. The door 20, 20′ is further configured to allow the flow of air through the air flow path 18 when the door 20, 20′ is in a position other than the closed position. As used herein, the term “a position other than the closed position” refers to a position of the door 20, 20′ when the end 22 of the door 20, 20′ does not abut the housing wall 14, thereby allowing flow of air through the air flow path 18. It is to be understood that “the position other than the closed position” includes any position of the door 20, 20′ when air is allowed to flow through the air flow path 18, non-limiting examples of which include a completely open position and a partially open position. It is further to be understood that when the door 20, 20′ is in the partially open position, the door 20 may be, for example, 99% open, 0.1% open, or any position therebetween.
It is to be understood that the door 20, 20′ may have a number of different shapes including, but not limited to, a curved shape, a flat shape, a barrel shape, or the like.
It is further to be understood that the end 22 of the door 20, 20′ includes a door rim and a door seal. In the example shown in
Again with reference to
Laminar flow of the air flowing through the gap 24 may be due, at least in part, on a percentage of closure of the door 20, 20′, the speed of the air traveling through the air flow path 18, a smoothness of the housing wall 14, and a lack of extreme bends, curves, or other distortions in the air flow path 18. Other factors that may also affect the laminar flow through the gap 24 include, for example, the viscosity of the air and the density of the air.
It is to be understood that the substantially laminar high speed flow of the air through the gap 24 may induce the aforementioned undesirable whistle or other audible noise when the HVAC is operating. More specifically, the air flows, at the high speed, through the gap 24 and contacts the edge of the door seal 25, 25′. In the examples shown in
Without being bound to any theory, it is believed that the noise generated from the substantially laminar high speed flow of the air traveling through the gap 24 (and contacting the door rim 23 or the door seal 25) may be reduced by breaking up the air flow structure into several smaller structures. For example, if the air flow structure is an air flow vortex, the laminar high speed flow may be reduced by breaking up the vortex into several smaller vortices. When this occurs, air vibration in the gap 24 is substantially reduced, thereby reducing the noise in the HVAC system. It is to be understood that the several smaller structures (formed by breaking up the air flow structure) induce turbulent flow of the air flowing through the gap 24. Still with reference to
In an embodiment, the noise-reducing feature 28 includes a plurality of protrusions defined on at least a portion of the housing wall 14. As shown in
In a non-limiting example, the plurality of protrusions 28 is substantially uniformly arranged on housing wall 14. For example, as shown in
Regardless of the arrangement of the protrusions 28, all of the protrusions 28 may be substantially uniform in size, in one non-limiting example. In a further non-limiting example, if the protrusions 28 have a circular cross-section, each protrusion 28 has a diameter D2 ranging from about 1 mm to about 3 mm, and each as a height H ranging from about 0.5 mm to about 2 mm. It is to be understood that the shape, height, and/or diameter of the protrusions 28 may be adjusted in order to achieve i) the desired reduction in noise, and ii) a permissible amount of air flow through the gap 24. It is further to be understood that the shape, height, and/or diameter of the protrusions 28 is also adjustable with respect to an available space defined in the HVAC system 10 for defining the protrusions 28 on the wall 14.
In an example, the protrusions 28 are formed on the wall 14 above the door 20, 20′ (as shown in
It is further to be understood that the protrusions may otherwise be formed on at least a portion of the wall 14 located near a side of the door. For example, another embodiment of the HVAC system 10″ is depicted in
In an embodiment, the protrusions 28 are formed integrally with the wall 14, 14′. This may be accomplished by defining a pattern of the protrusions 28 in a mold used for forming the housing wall 14, 14′. More specifically, material used for the mold is removed at predetermined areas defining the pattern of the protrusions 28. Thereafter, the wall 14, 14′ is formed including the protrusions 28 by injecting a material (e.g., a plastic or other suitable material for the housing wall 14) into the mold.
In another embodiment, the protrusions 28 are formed in a separate component via any suitable forming process such as, e.g., injection molding. The separate component is thereafter attached to the housing wall 14, 14′ via a suitable attachment means. In a non-limiting example, the attachment means is an adhesive. In another non-limiting example, the attachment means is a welding material established by, for example, hot plate welding, ultrasonic welding, heat staking, or the like. In yet another non-limiting example, the attachment means may be a mechanical attachment such as, for example, an interlock, a snap-fit, a fastener, or the like.
In yet another embodiment, the protrusions 28 are defined on the wall 14, 14′ via a machining process after the wall 14, 14′ is formed. Non-limiting examples of suitable machining processes include milling, laser machining, or the like.
Also disclosed herein is a method for reducing noise in the HVAC system 10. Using the embodiments of the HVAC system 10 described above, the method includes introducing air into the air flow path 18 and inducing turbulent flow of the air when the air contacts the noise-reducing feature 28.
To reiterate from above, the induced turbulent flow reduces the noise of the HVAC system 10. For example,
In the sound profile for the HVAC system without a noise-reducing feature (i.e.,
It is to be understood that the terms “above,” “below,” “near a side,” or the like are not intended to be limited to, nor necessarily meant to convey a spatial orientation, but rather are used for illustrative purposes to differentiate between different locations of the protrusions 28 relative to the door 20, 20′, 20″ in any spatial orientation (top, bottom, side, angularly offset, and/or the like).
While several embodiments have been described in detail, it will be apparent to those skilled in the art that the disclosed embodiments may be modified and/or other embodiments may be possible. Therefore, the foregoing description is to be considered exemplary rather than limiting.
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