GB2372052A

GB2372052A - Ridge tile for a roof, boiler flue terminal and boiler installation

Info

Publication number: GB2372052A
Application number: GB0129585A
Authority: GB
Inventors: Sandy Gataora
Original assignee: Gledhill Water Storage Ltd
Current assignee: Gledhill Water Storage Ltd
Priority date: 2000-12-12
Filing date: 2001-12-11
Publication date: 2002-08-14
Anticipated expiration: 2021-12-11
Also published as: GB0129585D0; GB2372052B; GB0030610D0

Abstract

A boiler installation comprising a fuel fired boiler, the flue gases from the boiler vent to the atmosphere through a roof ridge vent terminal. The terminal comprises a vent stack tube 52 though which flue gases from the boiler pass to the atmosphere though the top of the stack tube 52. The top of the stack tube 52 passes though a roof ridge tile 54, the tile being provided with an aperture 56 to receive the stack tube, and an outer sealing collar 58 around the aperture 56. The roof ridge tile 54 is otherwise identical to a conventional ridge tile 14. The stack tube has formation engaging the collar 58 to form a seal therewith. Flue gases pass up the flue pipe 50 into the chamber 62, around the stack tube 52, through the slots (76 fig. 4) and vertically out of the top of the stack tube. The invention applies particularly to condensing boilers.

Description

Ridge Tile for a roof, Boiler Flue Terminal and Boiler Installation This invention relates to a ridge tile for a roof for reception of a boiler flue terminal, and an installation including a boiler, terminal structure, and roof tile.

In the installation of a heating boiler in a domestic dwelling, two types of fuel fired boiler have been used, referred to hereinafter for the purposes of this specification, as the conventional type (non condensing) and the condensing type. As might be expected, a condensing boiler is of more modern vintage than the conventional type, in that in the condensing boiler, the boiler is designed to be of higher efficiency than the conventional type. To make it more efficient, the condensing boiler converts more of the available calories in the fuel into heat, and this means that the temperature of the flue gases from the condensing boiler is less than those of the conventional boiler. In consequence, the flue gases in the condensing boiler are designed to condense out the moisture content in the flue gases, and the boiler is designed to collect the condensate.

In domestic dwellings wherein condensing boilers are used, the boiler is usually located adjacent an outside wall of the building. The flue is usually exhausted to atmosphere through an outside wall terminal or through a terminal extending (up to a height of one metre or more) from a roof portion adjacent the wall of the dwelling. The wall terminal is objected to in that clouds of water vapour tend to be created in the vicinity of the wall terminal, and as regards the roof terminal, objection to this is taken as it projects too high above the roof and is considered unsightly.

The conventional boiler flue has been directed to specially designed roof ridge terminals, but these are vent like structures which direct the flue gases down onto the roof and are quite unsuitable for the venting of the cooler flue gases which are created by the condensing boilers, for a number of reasons.

Thus, the vent structure if used with a condensing boiler would direct condensate down onto the roof tiles, and in the fullness of time, such condensate and flue gas constituents dissolved therein would discolour and penetrate the roof tiles (especially concrete roof tiles which are now commonly used) and cause them quite literally, in some circumstances, to rot. Also, the vent structure used with conventional boilers has relatively poor sealing, and any condensate which collects in the vent structure, and inside the dwelling runs back towards the boiler, and if the boiler is of the conventional type, would simply flow along the line of least resistance to locations where it could cause damage, as conventional boilers are not designed to collect the condensate. Similarly, the condensate could also damage the building fabric if it is not collected and discharged properly.

Again, if a conventional vent structure were to be used with a condensing boiler, in cold weather, either ice slabs could form in the vicinity of the vent, or the vent could become blocked by snow and ice (resulting from the freezing of the condensate) and in consequence could stop the boiler from working and generate service calls. Conventional roof ridge vent structures are designed to be used with naturally venting boilers, and are not useable with fan vented boilers, which condensing boilers usually are. Finally, having regard to their design, the conventional roof ridge vents structure is relatively expensive to produce. The present invention, at least in its preferred form, addresses these problems. According to the present invention, there is provided in its broadest aspect, a boiler installation, comprising a boiler, which may be condensing, but may be non condensing and wherein the boiler vents to a roof ridge vent terminal comprising a vent stack tube through which flue gases from the boiler pass to atmosphere through the top of the stack tube, which top passes through a roof ridge tile provided with an aperture to receive the stack tube. The terminal may be for example as set forth in European Patent Application No. 0679841 Bl. Such a terminal defines an annular flue gas diffuser at the top of the stack tube, which is bounded by an upper plate which is dished outwardly to deflect the flue gases issuing therefrom into the atmosphere in a direction outwardly and upwardly of the roof ridge. By this means at least some of the condensing moisture in the flue gases and the flue gases will be swept away by the movement of the air surrounding the terminal. The roof ridge tile is preferably otherwise of the same construction as the other roof ridge tiles in the roof.

By using a stack tube and connecting it to the flue pipe, it is easy to make a sealed connection, so that moisture collecting in the stack tube which is not swept away by the outside air movement, will drain back to the boiler, which is designed to receive and dispose of it, and the moisture will not flow into the roof space through which the flue pipe passes. The stack tube may be of metal or plastics material.

By means of the invention, the condensing moisture in the flue gases and the flue gases will exit directly upwards out of the stack tube, and the stack tube can be made to extend only by the minimum amount from the top of the ridge tile, making it invisible or at least almost invisible to people on the ground. Although in one embodiment the stack tube is closed at the bottom, and condensate may collect therein, in order to overcome this, there may be a small hole in the bottom of the stack tube to allow the collected condensate to drain back into the boiler flue pipe.

Condensing boilers are designed to accommodate this drain back. By using a stack tube and connecting it to the flue pipe, it is easy to make a connection which provides sealing and prevents displacement between the stack tube and the flue pipe, so that moisture collecting in the stack tube will not flow into the roof space through which the flue pipe passes.

The roof ridge tile through which the stack tube passes may be provided with a flange around which the terminal fits, to form a seal, and to keep the stack tube in position. By the invention, a condensing boiler can be used with confidence, and even in the centre of the dwelling (i. e. not near an outer wall) Also, the invention extends to a roof ridge tile per se, which has the features indicated above, for use in a roof ridge.

Finally, the invention also extends to the combination of the aforesaid roof ridge terminal and roof ridge tile.

Embodiments of the invention will now be described by way of example, with reference to the accompanying drawings, wherein ; Fig. 1 is a diagrammatic perspective view of a conventional roof ridge terminal; Fig. 2 is a sectional elevation of the terminal of Fig. 1, taken on the line X-X in Fig. 1; Fig. 3 is a diagrammatic perspective view of a roof ridge terminal according to the embodiment of the invention; Fig. 4 is a sectional elevation of the roof ridge terminal shown in Fig. 3; and Figs 5 and 6 are views similar to Fig. 4 showing alternative embodiments.

Referring to the drawings, and firstly to Figs. 1 and 2, these figures show part of a roof structure which is basically of conventional form and is made up of roof tiles 10,12 which lie to opposite sides of ridge tiles 14 and slope downwardly as shown clearly in Fig. 2.

One of the conventional roof tiles 14 is replaced by the terminal block 16 by which flue gases from a boiler flue 18 are discharged into the atmosphere as indicated by the arrows 19 and 20. The arrows 19 indicate that the flue gases are discharged along the length of the roof ridge, whilst the arrows 20 show that the flue gases are projecting downwardly along the surfaces of the roof tiles 10 and 12.

The terminal block 16 comprises curved concrete components comprising a cap 22 of the rectangular, curved configuration shown provided with support feet 24 so as to define apertures through which the flue gases are ejected, these apertures being covered by metal grills 26 and 28. The cap 22 stands on a base 30, which generally speaking, is of similar configuration to one of the conventional ridge tiles 14, except that it has an elongated central slot 32 through which the flue gases, indicated in Fig. 2 by arrow 34 can pass into the space within the cap 22. The slot 32 is surrounded on the underside by a sealing gasket 35, and this gasket is compressed between the underside of the base 30 and a duct fitting 36, by means of clamping screws 38. The duct 30 and 36 has a peripheral flange 39 and then a widening portion 40 in which is provided a coupling cylindrical sleeve 42 in sealing engagement with the flue pipe 18. The structure described is of conventional form and is used with conventional boilers i. e. not condensing boilers, and whilst this terminal block works satisfactorily with non-condensing boilers, because the flue gases where they issue from the terminal block 16 would be of relatively high temperature, this structure is unsuitable for use with condensing boilers, for the reasons explained hereinbefore. The invention provides a different structure for the flue terminal by providing a new form of roof ridge tile, and one example is shown in Fig. 3. Fig. 3 is a view similar to Fig. 1, but showing the novel form of roof ridge tile, for use with a condensing boiler. The condensing boiler flue is shown at 50, and a terminal, which is in metal in this example, for use with the roof ridge tile, is shown at 52. Again, conventional ridge tiles 14 are shown as are conventional roof tiles 10 and 12 of the same configuration as those already described in relation to the embodiment of Figs. 1 and 2.

The novel form of roof ridge tile 54 is more or less identical to tile 14 except for the provision of an aperture 56 provided centrally therein, and an upstanding flange 58 which surrounds the aperture as shown in Fig. 3.

The terminal 52 as shown in Fig. 4, is generally a cylindrical stack tube 53 of open topped, closed base, hollow form, and at the top has a flange fitting 57 comprising a top rim 55 and a downwardly turned flange 56. The closed base of the structure is shown at 58, and the base has a drain hole 60 for the draining of condensate and melted snow. The drain hole 60 may be temporarily closed by means of a removable drain plug. The drain plug can be removed for cleaning and servicing. The flue system may have a temperature sensor in the vicinity of the drain plug. This sensor is linked to the boiler control system and the boiler fires if the terminal is about to freeze.

By this construction, the stack tube in use forms a collector for snow and also acts as a bird trap, preventing birds from dropping into the boiler flue 50. The terminal 52 also comprises an outer metal sleeve chamber 62 having an upper reduced diameter fitting 64 and a lower reduced diameter fitting 66 respectively for coupling the chamber 62 to the stack tube 52 and the flue pipe 50. Each of the fitting 64 and the top of the flue pipe 50 has a circumferential groove 68,70 for the receipt of a sealing gasket 72,74 as shown in Fig. 4.

As also shown in Fig. 4, the chamber 62 is of considerably larger diameter than the stack tube 52, which it receives, and the wall of the stack tube 52 has slot means in the form of axial and parallel slots 76 of equal length. The stack tube is connected to the chamber 62 by means of a clamping ring 78 which ensures that the stack tube 52 and the chamber remain in relatively fixed relationship and the stack tube cannot be pushed up nor the chamber be pushed down. The seals 72 and 74 ensure that the flue gases cannot leak out of the terminal at the joints between the flue pipe 50 and the chamber 62, and the chamber 62 and the stack tube 52.

Where the stack tube 52 seats on the ridge tile, and only a very small portion of the stack tube projects above the ridge tile, there is an annular gasket 80 which engages and overlaps the upstand 58, forming a weather seal therewith and also allowing a certain amount movement between the stack tube and the upstand 58 due to differential expansion. As can be seen from Fig. 4, the stack tube lies largely under the roof of the building and is located inside the chamber 62 with generous clearance so that the flue gases, as shown by the arrows, pass up the flue pipe 50, into the chamber 62, around the stack tube 52, through the slots 76, and vertically out of the open top of the stack tube 52 directly to atmosphere. An effective and"invisible"terminal is provided for condensing boilers in which the boiler can be located anywhere in the building, including centrally, the flue gases are vented vertically avoiding discolouring and degrading of the tiles and the formation of ice slabs in winter, the rapid blocking of the terminal by snow and ice is avoided, the cost is kept to a minimum, aesthetically the terminal is excellent, and as there is no projection of the terminal above the ridge tiles, the terminal is less likely to suffer damage in gale conditions.

Figs. 5 and 6 show other embodiments in which the same advantages as mentioned above are achieved, and parts already described in relation to Fig. 3 will not be described again, but wherein the stack tube 52 is in plastics material especially for use in an all plastics flue system which recently has been approved for condensing boilers.

In Fig. 5, the stack tube is welded or otherwise bonded as at 88 to the underside of the tile 54, which in this case is of compatible plastic material. In Fig. 6, the arrangement is the same as that in Fig. 5, except that it is shown that the combustion air for the boiler is drawn from the roof space 90 into an annular space 92 around the flue pipe, as shown by the arrows. The air which travels to the boiler along this space 92 mixes with the boiler fuel and is burned, the waste products of combustion (flue gases) being returned through the boiler flue pipe 50, and the terminal 52,62 as described in relation to Fig. 3. Except for the points noted, the embodiments of Figs. 5 and 6 are constructed and operate similarly to the Fig. 3 embodiment, and have all the advantages of the embodiment of Fig.

3. Instead of the concentric pipe arrangement shown in Fig. 6, the combustion air may be supplied from the roof space 90 via a separate pipe. Also, the air may be drawn by a pipe from outside the building via a wall terminal. Other terminal constructions may be used, and alternative examples are set out in European Patent No. 0679841 Bl.

The invention may have even wider aspect in that it provides for the first time that a condensing boiler is vented to a roof ridge tile via a special tile construction, and the invention therefore is also considered to provide in its broadest aspect, a condensing boiler installation, wherein the boiler vents to a novel roof ridge tile to take a terminal of design appropriate to a condensing boiler.

Claims

Claims 1. A boiler installation, comprising a fuel fired boiler of which the flue gases vent to atmosphere through a roof ridge vent terminal and wherein the terminal comprises a vent stack tube through which flue gases from the boiler pass to atmosphere through the top of the stack tube, characterised in that the said top passes through a roof ridge tile provided with an aperture to receive the stack tube.
2. A boiler installation according to claim 1, wherein the said roof ridge tile is similar to the other roof ridge tiles apart from said aperture.
3. A boiler installation according to claim 1 or 2, wherein the said aperture is of a similar shape to the cross section of the stack tube top so that the top fits neatly in said aperture.
4. A boiler installation according to claim 1,2 or 3, wherein the said roof ridge tile has on the top surface an upstanding collar surrounding the aperture, which is engaged by a formation in the stack tube for forming a seal between the stack tube and the roof ridge tile.
5. A boiler installation according to claim 4, wherein there is a sealing gasket of flexible material between the collar and the formation.
6. A boiler installation according to any preceding claim, wherein the top of the stack tube is open.
7. A boiler installation according to any preceding claim, wherein the roof ridge tile is of plastics material and the stack tube is bonded thereto where it passes through the tile.
8. A boiler installation according to any preceding claim, wherein the stack has slot means in the wall, and is closed at the base, and connects to the end of the boiler flue pipe via a top chamber of the flue pipe so that the flue gases from the boiler pass into the chamber then through the slot means, before exiting to atmosphere.
9. A boiler installation according to any preceding claim, wherein the boiler is a condensing boiler.
10. A boiler installation substantially as hereinbefore described with reference to the accompanying drawings.
11. A ridge tile for a roof, which tile includes a hole for receipt of a stack tube through which flue gases from a fuel fired boiler can issue to atmosphere.
12. A ridge tile according to claim 11, wherein on the upper surface of the tile, and surrounding the hole is a sealing collar for engagement with a formation on the stack tube.
13. A ridge tile according to claim 11 or 12, wherein the hole is circular.
14. A ridge tile substantially as hereinbefore described, with reference to the accompanying drawings.
15. A flue terminal for a ridge tile according to claim 12, wherein the terminal has a stack tube which is for location in the tile hole, and includes a formation for sealing engagement with the sealing collar.
16. A flue terminal for a ridge tile substantially as hereinbefore described with reference to the accompanying drawings.