GB2362926A

GB2362926A - Ventilation system

Info

Publication number: GB2362926A
Application number: GB0104385A
Authority: GB
Inventors: Robert Alan Gladden
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-02-22
Filing date: 2001-02-22
Publication date: 2001-12-05
Anticipated expiration: 2021-02-22
Also published as: GB0004094D0; GB0104385D0; GB2362926B

Abstract

A ventilation system comprises a fan 12 mounted in a flat oval sectioned casing (13 figure 5) which may be connected at either end to duct of the same cross section using flanges 16. The casing (13 figure 5) may be a double walled construction with an inner wall 17 and outer wall 18 sandwiching a noise reducing acoustic material 20. The walls 17, 18 may be perforated and may be produced from helical strips of material. The fan 12 may be suspended from a frame 31 inside the casing (13 figure 5) by springs 30.

Description

2362926 1 VENTILATION SYSTEM This invention relates to a ventilation or

air movement system. Conventionally a ventilation system locates a fan in a rectangular sectioned box which is then connected to incoming and outgoing duct-work of a different section from that of the box containing the fan. This is aesthetically unattractive so the system is usually hidden behind a suspended ceiling or the like.

Flat oval sectioned duct-work is sometimes used and has some advantages over rectangular sectioned duct-work. However, where used, it has conventionally been used with a fan in a square sectioned casing with the ingoing and outgoing duct-work unmatched to the fan casing. This is both of unpleasing appearance and inefficient.

An object of the present invention is to provide a ventilation system using flat oval sectioned ducting with a more pleasing appearance and preferably with greater attenuation and performance.

In one aspect the present invention provides a ventilation system in which a fan is mounted in a flat oval sectioned casing which is connected to incoming and outgoing duct sections of substantially the same crosssection as the casing. Preferably the flat oval sectioned casing in which the fan is mounted is of double skin construction with acoustic material between the skins. The fan is preferably isolated from the casing walls. In the preferred form the fan is suspended on springs, preferably suspended from a frame structure itself spaced from the interior oval wall of the casing and connected to end flanges of the oval casing.

The fan outlet is connected by a flexible tube to a spigot defining an opening in an oval end plate of the casing. The outgoing duct portion is also of double skin construction with acoustic material between the skins. Additionally the lower part, preferably the lower half, of the outgoing duct is filled with acoustic material. The inlets of the passage in the outgoing duct connects in a straight line with the outlet of the fan.

The incoming attenuation duct portion has a narrow central oval channel, having a cross-sectional area preferably between 25 and 50 % of the duct area, with the channel surrounded by acoustic material. This increases the resistance to flow and more nearly matches the airflow through the ingoing and outgoing ducts with that of the fan to increase performance. The ingoing and the outlet duct portions are themselves novel and may be claimed separately.

One embodiment of the ventilation system, in accordance with the invention, will now be described, by way of example only, with reference to the accompanying drawings of which:- Figure 1 is an outline arrangement showing a fan in an oval sectioned casing connected with similar oval sectioned incoming and outgoing duct portions; Figure 2 is a diagrammatic end view of the duct portions and fan of Figure 1; Figure 3 is an isometric view of the fan support frame and plate detail; Figure 4 is a sectional elevation of the fan support frame and casing.

Figure 5 is a perspective view of the casing, without end plate or fan, and Figure 6 is a perspective view of the outlet ducts portion.

Figures 1 to 3 show a centrifugal fan 12 located in a flat oval sectioned casing 13 connected at opposite ends to flat oval sectioned incoming and outgoing duct portions 14, 15, of the same cross-section. The end walls of the casing and duct portions are formed with flanges 16 by which they are connected together. The general 3 appearance is one of a continuous duct, which provides a pleasing appearance and may eliminate the need for the ducting to be placed behind a suspended ceiling or the like.

The oval sectioned casing 13 and outgoing duct portion 15 have a double skin construction with inner and outer walls 17, 18, holding between them a lining of acoustic material 20. As seen in Figures 5 and 6, the inner wall 17 is perforated. Alternatively or in addition the outer wall 18 is perforated. As one example, the dimensions in mm of the widths and heights of the casing and duct portions as shown in Figure 2 may be W1 632, W2 686, HI 305 and H2 356 with, for example, the length of the casing 13 being 560.

The outlet 21 of the fan is in the upper half of the casing and is connected by a flexible connecting tube 22 to a spigot 23 in the upper half of a flat oval outlet end plate 24 of the casing. The lower half of the outgoing duct 15 is filled with acoustic material 26 with the upper half inlet providing a passage connecting in a straight line with the outlet of the fan. As seen diagrammatically in Figure 6, this passage can also be shaped by inserts 25 of acoustic material.

The flat oval incoming duct portion 14 defines a flat oval central passage 27 of considerably smaller cross-section than that of the duct, for example one quarter the cross-sectional area. The passage 27 is surrounded by acoustic material 28. The reduction of the passages in these ducts by insertion of acoustic material improves the attenuation of noise, and increases the resistance to air flow so as to more nearly match the air flow through the fan. This increases the performance of the fan.

Figure 4 shows the fan 12 is mounted on four springs 30 at each side thereof, the springs being suspended from a sheet steel angle frame 31. This isolates the fan to avoid vibration of the casing and reduces noise. The frame itself is preferably spaced from the inner oval wall 17 of the casing and connected at each end to an inwardly projecting edge 32 of the end of the casing.

4 Figures 5 and 6 show the outer wall of the casing produced from a helical strip of material.

Claims

1. A ventilation system in which a fan is mounted in a flat oval sectioned casing which is connected to incoming and outgoing duct sections of substantially the same cross-section as the casing.

2. A ventilation system according to claim 1 wherein the flat oval sectioned casing in which the fan is mounted is of double skin construction with acoustic material between the skins.

3. A ventilation system according to claim 1 or 2 wherein the fan is preferably isolated from the casing walls.

4. A ventilation system according to any preceding claim wherein the fan is suspended.

5.

A ventilation system according to claim 4 wherein the fan is suspended on springs.

6. A ventilation system according to claim 4 or 5 wherein the fan is suspended from a frame structure itself spaced from the interior wall of the casing.

7.. A ventilation system according to any one of claims 2 to 6 wherein the double skin construction comprises an inner wall and an outer wall wherein the inner wall is perforated.

A ventilation system according to any preceding calim wherein the inner and outer walls of the casing are produced from a helical strip of material.

9. A ventilation system substantially as shown in or as described with reference to the accompanying drawings.