GB2145507A

GB2145507A - Balanced flue for gas fired appliance

Info

Publication number: GB2145507A
Application number: GB08417672A
Authority: GB
Inventors: Alan Beaton
Original assignee: Baxi Partnership Ltd
Current assignee: Baxi Partnership Ltd
Priority date: 1983-08-23
Filing date: 1984-07-11
Publication date: 1985-03-27
Also published as: GB8322602D0; GB8417672D0

Abstract

A gas-fired appliance has a balanced flue system comprising separate air inlet and flue products ducts (12, 11) connected to the appliance, and a transistion box (14) within which the air inlet duct (12) terminates and through and beyond which the flue products duct (11) extends. The two ducts may be disposed in parallel side-by-side relationship or they may follow distinct separate paths coming together at the transistion box. <IMAGE>

Description

SPECIFICATION Gas-fired appliances This invention relates to gas-fired appliances, especially but not exclusively gas-fired convectors, but relates more particularly to a balanced flue system for use with such appliances.

It is an object of the present invention to provide a balanced flue system for a gas-fired system which can be fitted into locations within domestic premises especially where for various physical reasons, for example actual position of the appliance (hall heater without convenient external wall) or dimensional restrictions, it has not hitherto been possible to employ a balanced flue system.

According to the present invention therefore there is provided a balanced flue system for a gas-fired appliance, the system comprising separate air inlet and flue products ducts connectible to the appliance, and a transition box within which the air inlet duct terminates and through and beyond which the flue products duct extends.

Preferably the two ducts are disposed in parallel side-by-side relationship.

Preferably, the two ducts extend laterally of the appliance. They may, of course, extend rearwardly, or upwardly, or upwardly and laterally. They may also follow distinct separate paths coming together at the transition box.

The ducts are preferably enclosed in insulation. The transition box may also be insulated.

The provision of the transition box allows the flue system to be fitted through different wall thicknesses, i.e. it can be dimensioned to suit requirements.

An outlet grille is preferably fitted to the outer end of the transition box which grille terminates in a deflector plate to guide flue gas products away from the balanced flue system.

A division plate is preferably provided in the grille to ensure the majority of the air enters the flue system rearwardly of the outlet of the flue products.

Preferably an air inlet space is provided around the flue product duct outlet to counteract any tendency of flow-back of the flue gases under action of wind.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which; Figure 1 is a perspective view of a gas-fired convector with a balanced flue system according to the invention; Figure 2 is a fragmentary perspective view, to an enlarged scale, of the air inlet/flue gas outlet of the flue system; and Figure 3 is a perspective detail view of a convector showing different flue system paths.

A gas-fired convector heater is generally indicated at 1 0. It is of conventional construction and will not be described in detail. Suffice it to say that within the convector 10 is a chamber divided by a splitter plate to maintain in separation incoming primary combustion air and outgoing flue gas products. To the air and flue gas compartments of this chamber is connected the balanced flue system of the present invention.

The balanced flue system comprises two laterally-extending, vertically-spaced, parallel, side-by-side, separate ducts 11 and 1 2 enclosed by an insulating cover 1 3. The ducts 11 and 1 2 lie along, say, the wall of a hall of a house. The upper duct 11 is the flue gas exhaust duct of the flue system, while the lower duct is the primary air inlet duct.

It will be manifest that these ducts 11, 1 2 need not be vertically spaced and, as can be seen from Fig. 3 they may egress from either side or the top of the convector 10, and they may change direction (not shown) or extend out of te back of the convector 10. They may also for part of their paths lie in different directions. The fact that they are separate allows the installer considerable scope in the physical layout of the convector or other gasfired appliance and the balanced flue system fitted thereto.

The flue gas duct 11 extends completely through a transition or collection box 1 4 to open into an open space exterior to the house or other premise and enclosed by a cage-like grille 1 5 secured to the end of the box 14.

The air duct 1 2 stops inside the transition or collection box 14 preferably just inside the end of the latter remote from the grille 1 5 although it can, of course, extend further in as required.

At the grille-end of the box 14 is a division plate 1 6 substantially closing the bottom half of the box 14. This ensures the majority of the air enters the flue system rearwardly of the outlet of the flue products.

The end of the cage-like grille 1 5 remote from the transition box 1 4 is closed by a deflector plate 1 7 which assists in directing the flue gases away from the wall 1 8 of the house or other premise.

From Fig. 2 which shows the flue system traversing a cavity wall it can be seen that the majority of the air (white arrows) enters the transition box 14 through the grille 15 rearwardly of the outlet of the flue gas duct 11 and then flows along the duct 12. Air also enters the box 14 via the air gap defined by the box wall and plate 1 6 around the region of the flue gas duct outlet to resist flowback of flue gas products, the flow path of which is indicated by black arrows.

It will be manifest that the transition box 14 can be dimensioned to suit different thickness of cavity or solid walls.

The separation of air and flue gases by the ducts 11 and 1 2 keeps the incoming air cooler than in conventional balanced flue systems thereby improving the combustion characteristics of the appliance.

The positions of the ducts 11 and 1 2 may, of course, be reversed if desired.

It is also an advantage of the balanced flue system of this invention that there is complete separation of the air and flue gases until the appliance-remote end of the system.

Finally, the present invention is also a gasfired appliance in combination with a balanced flue system as defined, described and illustrated herein.

In a modification (see Fig. 4), the transistion box 1 4A extends from the grille 1 SA to the gas-fired convector heater 1 or. In this instance, the upper flue exhaust duct 1 1A extends the full length of the transistion box 1 4A between the convector heater 1 0A and the grille 1 SA while the separate primary air inlet duct 1 2A extends into the transition box 1 4A from the convector heater for just a short distance.

The spacings (air gaps) between the- ducts 11 A, 1 2A and the transistion box 1 4A are selected to give the necessary heat insulation so that the insulating cover 1 3 can be omitted. This latter factor plus the reduced length of the duct 1 2A assists in reducing the cost of the modified arrangement of Fig. 4 compared with that of Figs. 1 to 3.

Claims

1. A balanced flue system for a gas-fired appliance, the system comprising separate air inlet and flue products ducts connectible to the appliance, and a transition box within which the air inlet duct terminates and through and beyond which the flue products ducts extends.

2. A balanced flue system as claimed in claim 1 in which the two ducts are disposed in parallel side-by-side relationship.

3. A balanced flue system as claimed in claim I or 2 in which the two ducts are adapted to extend laterally of the appliance.

4. A balanced flue system as claimed in claim 1 or 2 in which the two ducts are adapted to extend rearwardly, or upwardly, or upwardly and laterally, of the appliance.

5. A balanced flue system as claimed in claim 1, in which the two ducts are adapted to follow distinct separate paths coming together at the transitiqn box.

6. A balanced flue system as claimed in any one of claims 1 to 5 in which an outlet grille is fitted to the outer end of the transition box, which grille terminates in a deflector plate to guide the flue gas products away from the balanced flue system.

7. A balanced flue system as claimed in claim 6, in which a division plate is provided in the grille to ensure the majority of the air enters the flue system rearwardly of the outlet of the flue products.

8. A balanced flue system as claimed in any one of claims 1 to 7 in which an air inlet space is provided around the flue product outlet to counteract any tendency of flow-back of the flue gases under action of wind.

9. A balanced flue system as claimed in any one of claims 1 to 8, in which the two ducts are enclosed in insulation.

1 0. A balanced flue system as claimed in any one of claims 1 to 9 in which the transition box is insulated.

11. A balanced flue system as claimed in any one of claims 1 to 8 in which the transition box extends the full length of the flue products duct.

1 2. A balanced flue system, substantially as hereinbefore described with reference to Figs. 1 to 3 or Fig. 4 of the accompanying drawings.

1 3. A gas fired appliance having a balanced flue system as claimed in any one of claims 1 to

12.