ACOUSTICALLY OPTIMIZED DRAIN SLOTS IN A FAN COIL DEVICE

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Application No. 63/718,028, filed November 8, 2024 and entitled, “ACOUSTICALLY OPTIMIZED DRAIN SLOTS IN A FAN COIL DEVICE.” The subject matter of this related application is hereby incorporated herein by reference.

BACKGROUND

Field of the Various Embodiments

The various embodiments relate generally to heating, ventilation, and air-conditioning (HVAC) technologies and, more specifically, to acoustically optimized drain slots in a fan coil device.

Description of the Related Art

Traditional fan coil products include a motor and fan assembly that move air across a heat exchanger. The heat exchanger heats or cools air passing through the unit. The heat exchanger often comprises hydronic water coils that perform the heating or cooling of air passing through the unit. The cooled or heated air exits the unit into ducting and eventually into a room or other space in a building in which the fan coil unit is installed or is otherwise connected. In a cooling mode, air is often cooled to the point where water condenses to remove moisture from the air. Condensation from the air must be safely drained from the unit to avoid damaging the unit or the interior space in which the unit is installed. Many fan coil units have drain slots or cutouts beneath or adjacent to the coils to allow for condensation to exit the unit and into a drain pan or other drain system. Because of the nature of a fan coil unit, air passing through the unit and across drain slots that are used for condensate evacuation affect the acoustic performance of the unit. Sound that is generated and/or escapes through the drain slots creates unwanted noise in the interior space of a building in which the unit is installed.

Accordingly, what is needed are techniques for implementing a fan coil unit with improved acoustic performance.

SUMMARY

According to various embodiments, an air-handling apparatus includes: a heat exchanger having a housing with a plurality of vertical walls wherein air flows through the housing and across the heat exchanger in a first direction; a drain pan or other drain system adjacent to the housing, wherein the drain pan or other drain system is configured to receive condensate drainage from the heat exchanger; and a plurality of drain slots extending from at least one of the plurality of walls through which condensate drains into the drain pan or other drain system, wherein the plurality of drain slots are oriented at an angle relative to the first direction.

At least one technical advantage of the disclosed design relative to the prior art is that the disclosed design enables condensate to be drained from a fan coil unit while also maximizing the acoustic performance of the unit. The acoustic performance of the unit is maximized by minimizing unwanted noise generated by air running across and exiting through prior art designs. By utilizing acoustically optimized drain slots that allow for efficient movement of air exiting the unit, the acoustic performance of the unit is improved. These technical advantages provide one or more technological advancements over prior art approaches.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the various embodiments can be understood in detail, a more particular description of the inventive concepts, briefly summarized above, may be had by reference to various embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the inventive concepts and are therefore not to be considered limiting of scope in any way, and that there are other equally effective embodiments.

FIG. 1 is a perspective view of a fan coil unit according to one or more embodiments of the present disclosure.

FIG. 2 is a perspective view of drain slots in a portion of a fan coil unit according to one or more embodiments of the present disclosure.

FIG. 3. Is a perspective view of acoustically optimized drain slots in a portion of a fan coil unit according to one or more embodiments of the present disclosure.

FIG. 4 is a perspective view of an acoustically optimized drain slot according to one or more embodiments of the present disclosure.

FIG. 5 is a simplified side view of a portion of a fan coil unit that incorporates acoustically optimized drain slots according to one or more embodiments of the present disclosure.

FIG. 6 is a simplified representation of a computational fluid dynamics (CFD) simulation of airflow exiting drain slots which are not acoustically optimized.

FIG. 7 is a simplified representation of a CFD simulation of airflow exiting an acoustically optimized drain slot according to one or more embodiments of the present disclosure.

Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth to provide a more thorough understanding of the various embodiments. However, it will be apparent to one skilled in the art that the inventive concepts may be practiced without one or more of these specific details.

The acoustic performance of fan coil units is a concern in the HVAC industry. Noise generated by a fan coil unit or other air moving products generally falls into one of three categories, sound escaping through the inlet of the unit, sound escaping through the discharge of a unit, and sound that is radiated by the unit. A major contributor to radiated sound is sound generated by air moving out of the unit through slots intended for draining condensate.

This disclosure includes examples of a fan coil unit with acoustically optimized drain slots through which condensate leaves the unit. Relative to conventional drain slots, the acoustically optimized drain slots reduce the velocity and turbulence of air escaping the unit through the drain slots. Lower velocity and lower turbulence of air escaping through the drain slots attenuates the noise generated, and thereby improves the acoustic performance of the unit.

FIG. 1 is a perspective view of a fan coil unit 100 according to an embodiment of the present disclosure. As shown in FIG. 1, fan coil unit 100 includes, without limitation, a fan 110, a heat exchanger 120, and a drain pan 130. Air enters fan coil unit 100 through an inlet adjacent to fan 110, in the direction indicated by inlet arrow 140, and is directed towards heat exchanger 120. Heat exchanger 120 includes one or more coils, such as hydronic coils, that heat or cool air passing through fan coil unit 100. When air is cooled by heat exchanger 120, gravity and air flow cause condensation in heat exchanger 120 to drain into drain pan 130 through drain slots (not shown). In some cases, a condensate pump evacuates water from the drain pan 130. Air cooled by heat exchanger 120 exits heat exchanger 120 in the direction indicated by outlet arrow 150. Although FIG. 1 shows a fan coil unit 100 with the drain pan 130, in some embodiments, a different drain system is used.

FIG. 2 is a perspective view of drain slots 210 in a portion of a fan coil unit 200 according to one or more embodiments of the present disclosure. Fan coil unit 200 includes, without limitation, heat exchanger 120 and drain slots 210. FIG. 2 shows a view of the bottom of a fan coil unit 200 with drain pan 130 hidden such that drain slots 210 in heat exchanger 120 are visible. As shown in FIG. 2, drain slots 210 in heat exchanger 120 are not acoustically optimized according to embodiments of the disclosure. In some embodiments, drain slots 210 are holes in a bottom housing of heat exchanger 120. In some embodiments, drain slots 210 are rectangularly shaped holes. In some embodiments, fan coil unit 200 has one or more rows of drain slots 210.

FIG. 3. Is a perspective view of acoustically optimized drain slots 310 in a portion of a fan coil unit 300 according to one or more embodiments of the present disclosure. Fan coil unit 300 includes, without limitation, heat exchanger 120 and acoustically optimized drain slots 310. Drain pan 130 is hidden in FIG. 3 so that the acoustically optimized drain slots 310 are visible. The acoustically optimized drain slots 310 allow condensate to escape heat exchanger 120 and simultaneously efficiently control airflow through the drain slots 210 to minimize the magnitude of noise radiating from the fan coil unit 300. In particular, the acoustically optimized drain slots 310 reduce the velocity of air exiting the drain slots 210 while allowing condensation to exit heat exchanger 120 to drain pan 130. The acoustically optimized drain slots 310 are oriented such that they are non-perpendicular relative to the bottom housing of heat exchanger 120. The acoustically optimized drain slots 310 are also oriented so that they are non-perpendicular relative to an inlet of the fan coil unit 300 that is upstream relative to the heat exchanger 120. The acoustically optimized drain slots 310 are oriented downwards toward the drain pan 130.

While the drain slots 210 and acoustically optimized drain slots 310 described in this disclosure include rectangularly shaped channels and are arranged in rows, one skilled in the art will understand that other drain slot shapes and arrangements, although not specifically described here, are within the scope and the spirit of this disclosure.

FIG. 4 is a perspective view of an acoustically optimized drain slot 310 according to one or more embodiments of the present disclosure. Acoustically optimized drain slot 310 includes, without limitations, inlet 420, outlet 440, and mounting holes 460.

Acoustically optimized drain slot 310 has an inlet 420 through which condensate and air flow in the direction represented by a drain slot inlet arrow 430. Condensate and air flow through the interior channel of acoustically optimized drain slot 310 and exit through outlet 440 in the direction represented by drain slot outlet arrow 450. In some embodiments, the dimensions of acoustically optimized drain slot 310 causes laminar airflow to be generated in acoustically optimized drain slot 310, and reduces airflow turbulence. In some examples, friction between the inner walls of acoustically optimized drain slot 310 and the air passing through acoustically optimized drain slot 310 can cause the velocity of the air to decrease. In some embodiments, lower velocity of air escaping through acoustically optimized drain slot 310 results in an attenuation of noise generated by air escaping through drain slot 210 and acoustically optimized drain slot 310.

As shown in FIG. 4, acoustically optimized drain slot 310 includes mounting holes 460 which are used with fasteners to attach acoustically optimized drain slot 310 to the bottom housing of heat exchanger 120. Although acoustically optimized drain slot 310 is shown in FIGS. 3 and 4 as a separate part mounted on the bottom housing of heat exchanger 120, in some examples, acoustically optimized drain slot 310 can be an integral part of heat exchanger 120.

FIG. 5 is a simplified side view of a portion of a fan coil unit 500 that incorporates acoustically optimized drain slots 310 according to one or more embodiments of the present disclosure. Fan coil unit 500 includes, without limitation, heat exchanger bottom housing 510, drain slot 210, and acoustically optimized drain slot 310.

Acoustically optimized drain slot 310 is fastened to heat exchanger bottom housing 510 such that the channel through acoustically optimized drain slot 310 is aligned with drain slot 210 at the contact area of acoustically optimized drain slot 310 and heat exchanger bottom housing 510. Acoustically optimized drain slot 310 extends outwardly toward drain pan 130. The channel of acoustically optimized drain slot 310 is configured such that the direction of air passing through the channel, represented by arrow 530, is at an angle α relative to the direction of the air passing through heat exchanger 120, represented by arrow 520. In some embodiments, α is an acute angle. In some embodiments, α is 45 degrees and is relative to the direction of airflow. In some examples, the exit plane of acoustically optimized drain slot 310 is not parallel to the plane of the heat exchanger bottom housing 510 at the location of drain slot 210.

FIG. 6 is a simplified representation of a computational fluid dynamics (CFD) simulation 600 of airflow exiting drain slots 210 which are not acoustically optimized. CFD simulation 600 includes, without limitation, heat exchanger bottom housing 510, drain slot 210, heat exchanger airflow represented by arrows 610, airflow near drain slot 210, represented by arrows 620, and airflow out of drain slot 210, represented by arrows 630.

In CFD simulation 600, airflow is represented by arrows, and the length of an arrow corresponds to the relative velocity of the air in the vicinity of the arrow. In CFD simulation 600, the airflow passing through heat exchanger 120 in the direction similar to outlet arrow 150 in FIG. 1 is represented by arrows 610. According to CFD simulation 600, drain slot 210 acts as a nozzle, accelerating airflow inside of heat exchanger 120 in the vicinity of drain slot 210 to a high velocity, represented by arrows 620. High velocity airflow also occurs out of drain slot 210, as represented by arrows 630. In some cases (not shown) CFD simulation 600 indicates the presence of turbulence in airflow inside and outside of heat exchanger 120. In some embodiments, a higher velocity of air escaping through drain slots 210 results in a higher magnitude of noise generated by the air escaping through drain slots 210.

FIG. 7 is a simplified representation of a CFD simulation of airflow exiting an acoustically optimized drain slot 310 according to one or more embodiments of the present disclosure. CFD simulation 700 includes, without limitation, heat exchanger bottom housing 510, drain slot 210, drain slot 310, heat exchanger airflow represented by arrows 710, airflow in drain slot 310, represented by arrows 720, and airflow exiting acoustically optimized drain slot 310, represented by arrows 730.

In CFD simulation 700, similar to CFD simulation 600, airflow is represented by arrows, and the length of an arrow corresponds to the relative velocity of the air in the vicinity of the arrow. In CFD simulation 700, the airflow passing through heat exchanger 120 in the direction similar to outlet arrow 150 in FIG. 1 is represented by arrows 710. In CFD simulation 700, air exiting drain slot 210 and flowing through acoustically optimized drain slot 310 is represented by arrows 720, and air exiting acoustically optimized drain slot 310 is represented by arrows 730. According to CFD simulation 700, air exiting drain slot 210 and flowing through acoustically optimized drain slot 310 and air exiting acoustically optimized drain slot 310 are of a similar velocity to air passing through heat exchanger 120. Relative to air exiting drain slot 210 in FIG. 6, air exiting acoustically optimized drain slot 310 has a slower velocity. In some embodiments, a slower velocity of air escaping through drain slots 210 and acoustically optimized drain slots 310 results in a lower magnitude of noise generated by the air escaping through drain slots 210 and acoustically optimized drain slots 310.

In sum, techniques are disclosed for a fan coil device, including a heat exchanger with a plurality of walls, a drain pain or other drain system configured to receive condensate drained from the heat exchanger, and one or more drain slots. The drain slots are acoustically optimized to reduce the velocity of air exiting the drain slots.

At least one technical advantage of the disclosed design relative to the prior art is that the disclosed design enables condensate to be drained from a fan coil unit while also maximizing the acoustic performance of the unit. The acoustic performance of the unit is maximized by minimizing unwanted noise generated by air running across and exiting through prior art designs. By utilizing acoustically optimized drain slots that allow for efficient movement of air exiting the unit, the acoustic performance of the unit is improved. These technical advantages provide one or more technological advancements over prior art approaches.

1. In some embodiments, an air-handling apparatus comprises a heat exchanger having a housing with a plurality of walls, wherein air flows through the housing and across the heat exchanger in a first direction, a drain pan adjacent to the housing, wherein the drain pan is configured to receive condensate drainage from the heat exchanger, and a plurality of drain slots extending from at least one of the plurality of walls through which condensate drains into the drain pan, wherein the plurality of drain slots are oriented at an angle relative to the first direction.

2. The air-handling apparatus of clause 1, wherein the plurality of drain slots are configured to reduce a velocity of air exiting the housing through the drain slots.

3. The air-handling apparatus of clauses 1 or 2, wherein the plurality of drain slots are further configured to reduce a turbulence of the air exiting the housing.

4. The air-handling apparatus of any of clauses 1-3, wherein the angle relative to the first direction is 45 degrees.

5. The air-handling apparatus of any of clauses 1-4, wherein the plurality of drain slots are angled away from the first direction of air flowing through the housing.

6. The air-handling apparatus of any of clauses 1-5, wherein the plurality of drain slots acoustically attenuate noise caused by air exiting the housing.

7. The air-handling apparatus of any of clauses 1-6, wherein the drain pan is installed onto the housing and wherein condensate gravity drains into the drain pan through the drain slots.

8. The air-handling apparatus of any of clauses 1-7, further comprising a fan located upstream from the heat exchanger, wherein the fan forces air from an inlet of the air-handling apparatus and through the heat exchanger.

9. The air-handling apparatus of any of clauses 1-8, wherein the fan forces air through an outlet of the air-handling apparatus that is located underneath the heat exchanger or downstream from the heat exchanger.

10. The air-handling apparatus of any of clauses 1-9, wherein the plurality of drain slots are oriented at a non-perpendicular angle relative to the housing.

11. The air-handling apparatus of any of clauses 1-10, wherein an exit of each of the drain slots is in a different plane relative to an underside of the housing.

12. The air-handling apparatus of any of clauses 1-11, wherein the plurality of drain slots are oriented at an acute angle relative to a direction of airflow entering the air-handling apparatus via an inlet that is upstream from the heat exchanger.

13. The air-handling apparatus of any of clauses 1-12, wherein the plurality of drain slots extend outwardly from the housing and toward the drain pan.

14. In some embodiments, a system for draining condensate from an air handler comprises a plurality of drain slots extending outwardly from a housing, wherein the plurality of drain slots receive condensate drainage from a heat exchanger within the housing, wherein air flows through the housing and across the heat exchanger in a first direction, and wherein condensate flows from the housing through the plurality of drain slots and into a drain pan adjacent to the plurality of drain slots.

15. The system of clause 14, wherein the plurality of drain slots extend outwardly from the housing and are angled away from the first direction of air flowing through the housing.

16. The system of clauses 14 or 15, wherein the plurality of drain slots are configured to reduce a velocity of air exiting the housing.

17. The system of any of clauses 14-16, wherein the plurality of drain slots acoustically attenuate noise caused by air exiting the housing.

18. The system of any of clauses 14-17, wherein the plurality of drain slots are oriented at a non-perpendicular angle relative to the housing.

19. The system of any of clauses 14-18, wherein the plurality of drain slots are oriented at a 45 degree angle relative to the housing and angled away from the first direction of air flowing through the housing

20. The system of any of clauses 14-19, wherein the plurality of drain slots extend outwardly from the housing and toward the drain pan.

The descriptions of the various embodiments have been presented for purposes of illustration but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Any and all combinations of any of the claim elements recited in any of the claims and/or any elements described in this application, in any fashion, fall within the contemplated scope of the present protection.

While the preceding is directed to embodiments of the present disclosure, other and further embodiments of the disclosure can be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. Moreover, in the above description, numerous specific details are set forth to provide a more thorough understanding of the various embodiments. However, it will be apparent to one skilled in the art that the inventive concepts may be practiced without one or more of these specific details.