GB2536222A

GB2536222A - Improved condenser unit

Info

Publication number: GB2536222A
Application number: GB1503927.4A
Authority: GB
Inventors: Gillatt Phil
Original assignee: SilentAire Group Ltd
Current assignee: SilentAire Group Ltd
Priority date: 2015-03-09
Filing date: 2015-03-09
Publication date: 2016-09-14
Also published as: GB201503927D0; WO2016142664A1

Abstract

An air conditioner condensing (outdoor) unit 100 comprises a housing 110 to house an air movement means 114 comprising a propeller fan 116 and having a heat exchange area 112 to one side of the air movement means. The condensing unit also has a helical unit 300 mounted to one side of the air movement means and comprises a plurality of fins 312, each being inclined to an axial direction of the air movement means. The fins may be tapered in the radial and axial direction and may be formed from sound insulating foam material, and impart a spiral pattern on the air flow that improves the efficiency of the fan by lowering strain placed on the motor. A second helical unit may be mounted on the other side of the fan. The fan may be driven by a centrally located motor 118 to define a doughnut shaped active area through which the air passes (fig 3). An air movement guide 200 made from sound insulating material may mounted on the motor and may comprise of a tapered body that tapers to a point towards the heat exchange area.

Description

Improved Condenser Unit The present invention relates to an improved condenser unit for use in an air conditioning system or the like.

Known condenser units are typically housed in an external environment, for instance, outside a building to which coolant fluid is supplied for use in an air-conditioning system. The condenser unit comprises a heat exchanger area over which air is drawn for the surrounding environment. Typically, the condenser unit has a cuboid housing with the heat exchanger located in the bottom of the housing. Here a propeller fan is mounted at the top of the housing to pull air through the heat exchanger. The sides of the housing are typically open to allow air to be pulled through the coils. Although some panels are used for strength and security The propeller fan includes a propeller and a motor. The motor drives the propeller. The motor is typically mounted centrally to the propeller and housing. Typically, the motor is mounted underneath the propeller. Consequently, air is moved through the propeller in a doughnut area. The housing usually encompasses the circumference of the propeller fan to create the outer circumference of the doughnut.

Recently, regulators have started placing requirements on condensing units to limit the operational sound output of the unit. As the units are often placed external to buildings but in populated areas, reducing the noise is advantageous and manufacturers are keen to provide quieter condenser units. It would also be advantageous to provide a solution to quieten the existing condensing units already installed.

It is an object of the present invention to provide an improved condenser unit to address one of the above or other disadvantages. It is a further aim to provide a condenser unit having improved noise output in operation. It is a further aim to provide a solution that can be easily retrofitted with minimal disruption to existing condensing units.

According to the present invention there is provided a condensing unit, a condensing unit silencer, and a kit of parts for retrofitting to existing condensing units to quieten the sound output, and a method of quietening existing condensing units as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the

description which follows.

According to the exemplary embodiments there is provided a condensing unit having an air movement guide arranged on a heat exchanger side of a motor. The motor is mounted to drive a propeller fan to draw air through the heat exchanger. The air movement guide comprises a tapered body extending from the motor toward the heat exchanger.

In the exemplary embodiments the tapered body extends from the motor a distance of at least 50% of the width of the motor. That is a distance from a centre of the tapered body to an edge at a base of the tapered body is less than the axial separation between the base and tapered distal end.

In the exemplary embodiments the sides of the tapered body are substantially straight.

Alternatively the sides are arcuate wherein a normal tangent of each location on the surface is angled to the axial direction.

In the exemplary embodiments, the tapered body is formed from sound insulating material such as foam or the like. The material may be coated so as to reduce air friction.

In a further exemplary embodiment, there is provided an air movement guide for fitting to a motor of a condensing unit. Here the air movement guide is substantially as described in relation to the previous aspect wherein the air movement guide is provided separately for retrospectively fitting to the motor.

According to a further exemplary embodiment, there is provided a condensing unit having a helical unit. The helical unit is arranged adjacent a propeller fan driven by a central rotation means such as a motor. The helical unit comprises a plurality of fins. Each fin extends from an outer circumference of the propeller inwardly. Advantageously, the fins act to impart a spiral pattern on the air movement as it moves there through, which has been found to improve the efficiency of the propeller fan such that a lower strain is placed on the rotation means.

In an exemplary embodiment, each fin extends substantially radially. The fins extend part way towards the central region aligned with the motor. Preferably the fins extend at least 10% or at least 14% and preferably 16% of the distance from the extent of the propeller and the central region shadowed by the motor. Preferably the fins extend less than 30% or less than 20% or less than 18% of said distance.

In one exemplary embodiment, the fins are pitched at least 15° or at least 20° and preferably 22.5°. In the exemplary embodiment, the fins are pitched less than 30° or less than 25°.

In one exemplary embodiment, the fins are tapered in the radial direction towards the centre of the propeller fan. Preferably or alternatively, the fins are also tapered in the axial direction towards the direction of air movement. In the exemplary embodiments, one of the surfaces of each fin is angled to the axial direction in order to impart the spiral pattern of air movement. Suitably the fins are slanted to the axial direction. Here the fins may be slanted between 50° and 70° or between 55° and 65° and preferably around 60°.

In one exemplary embodiment the axial height of the helical unit is between t 50% or I 40% of the distance in which the fins extend across the working area of the propeller fan.

In the exemplary embodiments, the fins are formed from sound insulating material such as foam or the like. The material may be coated so as to reduce air friction.

In a further exemplary embodiment, there is provided helical unit for fitting to a motor of a condensing unit. Here the helical unit is substantially as described in relation to the previous aspect wherein the air movement guide is provided separately for retrospectively fitting to the motor.

In a further exemplary embodiment there is provided a kit of parts comprising at least one of the helical unit or air movement guide according to one of the previous embodiments.

The kit of parts may also include the other of the helical unit or air movement guide. The kit of parts may also include sound insulating panels for lining the condensing unit.

In a further exemplary embodiment there is provided a method of retrofitting a condensing unit with a kit of parts of the previous embodiment. Here, the method may comprise rolling a flat strip with protrusions in to a continuous band wherein the protrusions extend inwardly and form the fins of the helical unit.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 is a perspective schematic view of a condenser unit according to an exemplary embodiment; Figure 2 is a top perspective view of a condenser silencer according to an exemplary embodiment: Figure 3 is a schematic bottom view of Figure 1; Figure 4 is a perspective view of a part used for the construction of an exemplary condenser silencer.

Referring to Figure 1 a condenser unit 100 is shown. A detailed description of the condenser unit will not be given as these units are widely know and it is envisaged that the improvements described herein can be applied with minimal adaption to different sizes and construction of known condenser units as well as being incorporated into new designs. Typically the condenser unit comprises a housing 110. The housing is shown as a cuboid but other shapes are envisaged. The housing encases an area divided into a lower, heat exchanger area 112 and an upper area housing an air circulation device 114. The air circulation device is arranged to draw air through the lower housing area and over the heat exchanger. Consequently air is expelled from the top of the housing into the environment.

The air circulation device 114 comprises a propeller fan 116 or the like that rotates to generate a negative pressure on the heat exchanger side. A motor 118 is mounted in the housing to rotate the propeller fan 114. The propeller fan is shown as being mounted on the underside of the propeller fan 114 and centrally to the housing and propeller fan. The motor is typically circular and has an outer motor housing of solid construction. Consequently, air does not move through the area covered by the motor. Air is therefore pushed away from the top of the housing in a circular, doughnut area defined at the outer circumferential edge of the propeller fan by the housing and a central circular area by the motor.

The propeller fan is typically spaced from the top of the housing. The top of the housing usually includes a grill 120 or the like that allows air to pass but acts as a barrier for debris or a safety barrier from accessing the moving parts.

In exemplary embodiments, the housing walls were lined with panels of sound insulating foam. Sound insulating foam is known in the art. Lining the walls has been found to reduce the sound output of the condensing unit by absorbing air movement and mechanical noise form the mechanical parts of the heat exchanger. The parts of the heat exchanger such as the compressor can also be lined with sound insulating material, which has been shown to also reduce noise output.

In one exemplary embodiment, the condenser unit includes an air guide device 200 fitted to the motor as shown in Figure 1. The air guide device extends from the motor 118 toward the heat exchanger area. The air guide device may be arranged within or partially with the heat exchanger area. The air guide devise is shown as a tapered body. Here, the tapered body has a lesser extend from a central axis at a distal end as compared to a base end. The base end is attached to the motor or at least mounted in close relationship thereto and the distal end extended towards the heat exchanger. The air guide device 200 is shown as having a conical shape. However, it will be appreciated that the base may have other shapes to suit the application. But it is advantageous that the air movement device 200 has substantial symmetry about the central axis so as to smooth air movement. Moreover, although the air guide device is shown as advantageously tapering to a substantial point, a stubbed end may also be suitable for particular applications.

The air guide device 200 has been found to reduce the noise output of the condenser unit. It is believed the reduced noise level is achieved by the air guide device encouraging smoother air flow through the doughnut operating area of the propeller fan. Consequently, the strain applied to the propeller fan and therefore motor is reduced. It is believed this causes a reduction in the mechanical noise generated by the motor as the motor has to work less hard to achieve the same throughput of air.

In a further exemplary embodiment, a helical unit 300 is arranged on the external side of the propeller fan 114. The helical unit 300 is located in the space between the propeller fan and top of the housing. To enable the helical unit to be retrofitted to existing condensers, the height of the helical unit is limited and needs to be sized accordingly. However, it will be appreciated that when incorporating a helical unit into new designs, the limitation is less of an issue. The helical unit is arranged to control the air movement pushed by the propeller fan. It has been found through smoke testing that existing condensers move the air in a mushroom shape such that the air moves upwards a limited extend before moving sideways and falling down. In contrast, it has been found that by adopting an air movement device as described herein, the air can be controlled to move away from the condenser significantly further before moving out and falling down. When the propeller fan is located on the top of the condenser unit, it will be understood that the air moves vertically away from the condenser. For instance, in a test environment using the exemplary helical unit, the height of the mushroom has been extended by up to 500%. It is believed that by extending the height of the mushroom as compared to a unit not employing the helical unit, the noise output can be reduced by increasing the negative pressure on the heat exchanger side of the propeller fan so that the propeller has to work less hard to move the same volume of air and consequently less strain is placed on the motor. The negative pressure is increased, that is the negative pressure gets more negative, because the air on the external side is encouraged to move away from the propeller fan more efficiently.

Referring to figure 2, an exemplary helical unit 300 is shown. The helical unit comprise a plurality of fins 310 extending inwardly from an external circumference of the helical unit 300. The fins 310 are spaced about the circumference are arranged to extend into the doughnut shaped operational area of the propeller fan. The fins do not extend across the doughnut. That is, from a top perspective as shown in Figure 3, the fins only extend partially towards the motor. In the exemplary embodiments the fins extend at least 10 % of the distance across the doughnut area between the outer circumference of the propeller fan and the motor housing.

Moreover, the fins extend less than 30% of the distance so that a substantial area of the doughnut is not affected. In a particular exemplary embodiment, the fins extend around 16 % of the distance and between 14% and 20%.

The fins are suitably arranged to extend inwardly in a radial direction. Advantageously, the fins are shown as being tapered towards a distal end and in the radial direction. In the figures, fins are shown as having a triangular cross section but other cross sections are envisaged including curved or arced sides. The triangular cross section may form a scalene triangle and in particular a right-angled scalene triangle. Furthermore, the fins are shown as having a substantial constant cross section. Again, it is envisaged that the cross section may be variable. Here, the fins would also be tapered in the axial direction wherein the tapered end extends towards the propeller fan. Where the fins are tapered, the angle or alignment of the fins is intended to relate to the major plane of the fin.

The helical unit 200 is arranged to impart a helical motion on the edge of the air being moved through the propeller fan. Consequently, the fins are slanted with respect to the axis of the propeller. That is, a part of a fin spaced towards the propeller is arranged at a different angular extent to another part of the fin. The fins may be angled in the direction of the action of the propeller or may be angled opposed thereto. However, the exemplary embodiments angle the fins in the same direction as an angle of the propeller fan. The angle of the fins in the exemplary embodiments is shown as around 60° to the axis of the propeller.

Referring back to Figure 2, the exemplary embodiment of the helical unit includes a circumferential body 312 from which the fins 310 extend. The body 312 is tubular. However, whist the internal surface is tubular so as to match the external extend of the propeller, the external shape may be sized and shaped according to the application. In the exemplary embodiments, the fins and body are formed from sound absorbing foam. Typically the foam would be coated to reduce the air friction and therefore reduce noise generation of the air moving over the parts. Here, and particularly where the helical unit is to be retrofitted, the helical unit includes a rigid carrier on the external surface of the body to provide support and rigidity thereto.

As shown in Figure 3, the body is arranged not to extend into the doughnut shaped operational area of the propeller fan. In use, the fins 310 extend into the operational area and act on the air to impart a helical nature to the air movement. This spiralling affect is thought to impart the spiral motion on the air that has the advantageous effect of increasing the height of the mushroom.

Referring to Figure 4, an exemplary method of forming the helical unit 300 is shown.

Here, the body is formed from a rectangular strip of material which is subsequently rolled into a circle to form the helical unit. As mentioned, suitably, the strip is a foam strip. Extending substantially orthogonally to the rectangular strip are upstanding protrusions that will form the fins. The protrusions are angled across the rectangular strip to provide the angle 0 on the fins. It will be appreciated that the angle across the rectangular strip defines the slant on the fins as described herein. Again as mentioned, the protrusions are shown as being triangular shaped, but other shapes are envisaged. The protrusions may be integrally formed, or alternatively the protrusions may be formed as separate pieces and affixed to the rectangular strip. A backing strip is applied to the rectangular strip, if needed to provide strength and stiffness. The part can then be rolled to form the helical unit. This is particularly useful for a retrofitting operation where the helical unit can be transported in a flat orientation before being formed. The helical unit may be formed from one part or multiple parts joined together to form a lengthened part for rolling. Again multiple parts may be advantageous when transporting the helical unit in smaller parts to be retrofitted on site.

It will be appreciated that the air movement device may be used in isolation or in conjunction with the helical unit. Furthermore, the noise output has also been shown to be reduced by placing a second helical unit on the heat exchanger side of the propeller fan. Here, the second helical unit is substantially in accordance with the first. The fins may be aligned in the radial extent. Consequently, a kit of parts for retrofitting an existing condenser is provided. The kit of parts comprises a helical unit or an air movement device as herein described or both. Furthermore, the kit of parts may further comprise insulating panels sized and arranged to be used to line the housing or other parts of the condenser unit.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Claims

Claims 1. A condensing unit comprising a housing to house an air movement means and to define a heat exchanger area to one side of the air movement means, wherein the condensing unit also comprises a helical unit mounted to one side of the air movement means, wherein the helical unit comprises a plurality of fins, wherein each fin is angled to an axial direction of the air movement means and each fin extends over a part distance of the active area of the air movement means.
2. The condensing unit of claim 1 wherein the air movement means is a propeller fan.
3. The condensing unit of claim, 1 or claim 2, wherein a motor is mounted centrally to the air movement means to therefore define a doughnut shaped active area of the air movement means.
4. The condensing unit of any proceeding claim wherein the fins are tapered in the radial direction.
5. The condensing unit of any proceeding claim wherein the fins are tapered in the axial direction.
6. The condensing unit of any proceeding claim wherein the fins are formed from a sound insulating material.
7. The condensing unit of any proceeding claim wherein the condensing unit further comprises a second helical unit mounted on the other side of the air movement means.
8. The condensing unit of any of claims 2 to 7 wherein the condensing unit further comprises an air movement guide arranged on the motor wherein the air movement guide comprises a tapered body that extends towards the heat exchanger area.
9. The condensing unit of claim 8 wherein tapered body is formed from sound insulating material.
10. A helical unit for retrofitting to a condenser unit, wherein the helical unit comprises a body and a plurality of fins, wherein each fin is angled to an axial direction of the body and each fin extends inwardly a part distance across an aperture in the body.
11. The helical unit of claim 10, wherein the body is a tubular body.
12. The helical unit of claim 10 or claim 11 wherein the body is formed from sound insulating material.
13. A kit of parts comprising a helical unit of any of claims 10 to 13 and an air movement guide comprising a tapered body for retrofitting to a motor of a condenser unit.
14. A method of silencing a condenser unit, the method comprising retrofitting a helical unit of any of claims 10 to 12 to a condenser unit.
15. The method of claim 14, wherein the helical unit is formed by rolling a strip having protrusions extending therefrom from a substantially flat state to a tubular state and affixing the rolled strip to the housing of a condenser adjacent an air movement means.