Glow-worm 56/3e Back Boiler - Manual (Page 8)

8 221725B
If a flue and false chimney breast are to be constructed all
openings for pipework to upper floors etc., must be sealed. The
only opening for the back boiler must be at the front, being of the
dimensions as shown in
diagram 1.2.
If a specially built compartment is constructed for the back
boiler, it must conform to the requirements of the current issue
of BS5440 Part 1 and BS5871.
The flue should, preferably, end above ridge height but at least
above the eaves of a pitched roof. Use a certificated terminal.
3.4 Ventilation - Back Boiler and Fire Front
It is important that the room in which the back boiler unit is
installed has adequate air inlets to ensure correct operation as
specified in the current issue of BS5440 Part 2.
Ventilation requirement for this back boiler is:
87cm 2 (13.5in 2 )
This ventilation area takes into account the total requirement of
the back boiler unit and any of the specially designed gas fire
fronts.
The ventilation openings may communicate direct with outside
air or with an internal room or space (such as a hall) which itself
is provided with a permanent air vent of the same effective area.
The permanent air vent should be in a position which minimizes
nuisance to occupants due to draughts.
This vent must NOT be placed in the builder’s opening.
If the appliance is to be installed in a room already containing
another fuel burning unit, the air supply required for this other
unit MUST be added to the figure above.
Any air vent taken through a cavity wall must be ducted.
3.5 Extract Fans
If an extract fan is fitted in the premises, there is a possibility that
if adequate air inlet openings are not provided spillage of the
products of combustion could occur.
When openings are fitted in accordance with the
recommendations of the current issue of BS5440 Part 2, extract
fans should not cause spillage.
Where such a fan installation is found, a clearance of products
test must be conducted as described in the fire front Installation
Instructions.
This test must be carried out with the back boiler fitted with its
fire front.
See also Section 6.3 of these instructions.
3 Flue and Ventilation