GB2165940A - Gas-fired heating appliance - Google Patents

Abstract

A caravan has a gas-fired convector heater (11) mounted on an internal wall. A balanced flue for the heater comprises a first combined section comprising an inner exhaust duct (16) and an outer air inlet duct (17). The ducts then separate, the exhaust duct extending upwardly through the roof of the caravan, the air duct extending downwardly through the floor. Because the air duct is cool it can pass through a useable cupboard. The exhaust duct is hot and passes through a narrow protective compartment (24). Thus the least possible useable space is lost. <IMAGE>

Description

SPECIFICATION Gas-fired heating appliance This invention relates to gas-fired heating appliances and to their fluing arrangements.

The invention provides a gas-fired heating appliance having a balanced flue having a first section adjacent the appliance in which an exhaust pipe runs inside an air inlet pipe, the exhaust pipe and air inlet pipe then separating, th exhaust pipe extending upwardly and the air inlet pipe downwardly.

The exhaust pipe may extend upwardly either behind the appliance or to one side of it. The exhaust pipe has a protective enclosure, either a ventilated compartment and/or an insulated covering.

The appliance is of particular use in a caravan or small dwelling in which there is an open air space beneath the floor. In such an installation the air inlet pipe passes downwardly through the floor to draw air from said open air space.

The heating appliance may be adapted to use bottled gas.

A specific embodiment of the invention is shown in the accompanying drawing, which is a side section through a gas-fired heating appliance.

The gas-fired heating appliance (11) is shown mounted in a caravan having an outer wall (19) and a floor (20). The appliance is a convector heater having a heat exchanger (12) through which convected air passes to be heated. The heater has a combustion air fan (not shown) which draws air for combustion into the heater. The heater uses a novel balanced flue system in which a first section (14) extends horizontally rearwardly from the heater. This section comprises an inner duct (16) within an outer duct (17). The outer duct (17) is closed off at its end and communicates with a vertical inlet down-pipe (18) which passes through the floor (20) to end in the open space beneath the caravan. A shield (21) protexts the open end of the duct (18).The inner duct (16) passes through the closed end of outer duct (17) and turns upwardly to form an up-pipe (23) adjacent wall (19) passing up through the roof of the caravan to end in a terminal (22).

The outer duct (17) and down-pipe (18) comprise their inlet to the heater and are cool, requiring no special precautions. Thus down-pipe (18) passes down through a useable cupboard space. The inner duct (16) and the up-pipe (23) leading to terminal (22), comprise the exhaust outlet for the heater and are hot. Therefore, the up-pipe (23) is contained in a narrow protective compartment (24) which may be ventilated to the outer atmosphere to keep it cool. Since up-pipe (23) contains the exhaust gases only it is of relatively small diameter, e.g. between 3cms and 5 cms, and compartment (24) need only be of small size, e.g. of the order of 9 cms deep.

Thus the minimum of space in the caravan is used in providing for the hot exhaust gases from the heater. It will be appreciated that the design of caravan interiors aims at using the limited space to the best advantage, and this invention aids this.

Although the specific embodiment shown in the drawing has the up-pipe (23) located directly behind the heater (11), pipe (16) may turn and extend horizontally, in or out of the plane of the drawing for a distance, up-pipe (23) then being located to one side or the other of the heater. Thus the heater (11) may be located centrally of the caravan, not on an outside wall.

1. A gas-fired heating appliance having a balanced flue comprising a combined section adjacent the appliance in which an exhaust pipe runs inside an air inlet pipe, the exhaust pipe and air inlet pipe separating at the end of the combined section, the exhaust pipe extending mainly upwardly and the air inlet pipe downwardly in normal use.

2. A heating appliance as claimed in claim 1, wherein said combined section runs horizontally rearwardly of the appliance in normal use.

3. A heating appliance as claimed in claim 1 or claim 2, comprising a convector heater having a combustion air fan.

4. A heating appliance substantially as described hereinbefore with reference to the accompanying drawing.

5. A caravan or small dwelling having an open air space beneath the floor having a heating appliance as claimed in any of claims 1 to 4, wherein said air inlet pipe extends to said open air space.

6. A caravan or small dwelling as claimed in claim 5, wherein said exhaust pipe extends through a roof of the caravan or small dwelling.

7. A caravan or small dwelling as claimed in claim 5 or claim 6, wherein said air inlet pipe extends through a useable cupboard space of the caravan or small dwelling.

8. A caravan or small dwelling as claimed in any of claims 5 to 7, wherein said exhaust pipe extends through a protective compartment in the caravan or small dwelling.

9. A caravan or small dwelling as claimed in claim 8, wherein said protective compartment is of the order of 9 cms deep.

10. A caravan or small dwelling substantially as described hereinbefore with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Gas-fired heating appliance This invention relates to gas-fired heating appliances and to their fluing arrangements. The invention provides a gas-fired heating appliance having a balanced flue having a first section adjacent the appliance in which an exhaust pipe runs inside an air inlet pipe, the exhaust pipe and air inlet pipe then separating, th exhaust pipe extending upwardly and the air inlet pipe downwardly. The exhaust pipe may extend upwardly either behind the appliance or to one side of it. The exhaust pipe has a protective enclosure, either a ventilated compartment and/or an insulated covering. The appliance is of particular use in a caravan or small dwelling in which there is an open air space beneath the floor. In such an installation the air inlet pipe passes downwardly through the floor to draw air from said open air space. The heating appliance may be adapted to use bottled gas. A specific embodiment of the invention is shown in the accompanying drawing, which is a side section through a gas-fired heating appliance. The gas-fired heating appliance (11) is shown mounted in a caravan having an outer wall (19) and a floor (20). The appliance is a convector heater having a heat exchanger (12) through which convected air passes to be heated. The heater has a combustion air fan (not shown) which draws air for combustion into the heater. The heater uses a novel balanced flue system in which a first section (14) extends horizontally rearwardly from the heater. This section comprises an inner duct (16) within an outer duct (17). The outer duct (17) is closed off at its end and communicates with a vertical inlet down-pipe (18) which passes through the floor (20) to end in the open space beneath the caravan. A shield (21) protexts the open end of the duct (18).The inner duct (16) passes through the closed end of outer duct (17) and turns upwardly to form an up-pipe (23) adjacent wall (19) passing up through the roof of the caravan to end in a terminal (22). The outer duct (17) and down-pipe (18) comprise their inlet to the heater and are cool, requiring no special precautions. Thus down-pipe (18) passes down through a useable cupboard space. The inner duct (16) and the up-pipe (23) leading to terminal (22), comprise the exhaust outlet for the heater and are hot. Therefore, the up-pipe (23) is contained in a narrow protective compartment (24) which may be ventilated to the outer atmosphere to keep it cool. Since up-pipe (23) contains the exhaust gases only it is of relatively small diameter, e.g. between 3cms and 5 cms, and compartment (24) need only be of small size, e.g. of the order of 9 cms deep. Thus the minimum of space in the caravan is used in providing for the hot exhaust gases from the heater. It will be appreciated that the design of caravan interiors aims at using the limited space to the best advantage, and this invention aids this. Although the specific embodiment shown in the drawing has the up-pipe (23) located directly behind the heater (11), pipe (16) may turn and extend horizontally, in or out of the plane of the drawing for a distance, up-pipe (23) then being located to one side or the other of the heater. Thus the heater (11) may be located centrally of the caravan, not on an outside wall. CLAIMS

1. A gas-fired heating appliance having a balanced flue comprising a combined section adjacent the appliance in which an exhaust pipe runs inside an air inlet pipe, the exhaust pipe and air inlet pipe separating at the end of the combined section, the exhaust pipe extending mainly upwardly and the air inlet pipe downwardly in normal use.

2. A heating appliance as claimed in claim 1, wherein said combined section runs horizontally rearwardly of the appliance in normal use.

3. A heating appliance as claimed in claim 1 or claim 2, comprising a convector heater having a combustion air fan.

4. A heating appliance substantially as described hereinbefore with reference to the accompanying drawing.

5. A caravan or small dwelling having an open air space beneath the floor having a heating appliance as claimed in any of claims 1 to 4, wherein said air inlet pipe extends to said open air space.

6. A caravan or small dwelling as claimed in claim 5, wherein said exhaust pipe extends through a roof of the caravan or small dwelling.

7. A caravan or small dwelling as claimed in claim 5 or claim 6, wherein said air inlet pipe extends through a useable cupboard space of the caravan or small dwelling.

8. A caravan or small dwelling as claimed in any of claims 5 to 7, wherein said exhaust pipe extends through a protective compartment in the caravan or small dwelling.

9. A caravan or small dwelling as claimed in claim 8, wherein said protective compartment is of the order of 9 cms deep.

10. A caravan or small dwelling substantially as described hereinbefore with reference to the accompanying drawing.