Air Supply - IDEAL Concord CXA 40/H Installation & Servicing Manual

VENTILATION
Safe, efficient and trouble-free operation of open flued gas
boilers is vitally dependent on the provision of an adequate
supply of fresh air to the room in which the appliance is
installed. Ventilation by grilles communicating to the outside
air is required. The minimum free area and required
positioning of these grilles must be in accordance with Tables
5 & 6.
Table 5 (to BS5440)
CXA 40/H-60/H boilers installed in a room or internal space
Boiler size
40
50
60
This air vent shall be direct to outside air or to a room or
internal space itself with an air vent to outside air of the same
size.
Table 6 (to BS6644)
CXA 70/H-120/H boilers
Required area (cm ) per kW of total rated input (net)
2
Low level (inlet)
High level (outlet)
Note: Where a boiler installation is to operate in summer
months (e.g. DHW) additional ventilation requirements
are stated, if operating for more than 50% of time (refer
to BS6644).
Position ventilation grilles to avoid the risk of accidental
obstruction by blockage or flooding. If further guidance on
ventilation is required then consult BS.6644 and BS.5440:2.:
2000
AIR SUPPLY BY MECHANICAL VENTILATION
The supply of air by mechanical means to a space housing the
boiler should be by mechanical inlet with natural or
mechanical extraction. Mechanical extract ventilation with
natural inlet must NOT be used.
Where a mechanical inlet and a mechanical extract system is
applied, the design ventilation flow rates should be as in Table
4 of BS.6644.
The requirements for air supply by mechanical ventilation are
given in BS.6644.
Note. For mechanical ventilation systems an automatic control
should be provided to cause safety shutdown or lockout of the
boiler(s) in the event of failure of air flow in either inlet or extract
fans.
IMPORTANT. The use of an extractor fan in the same room as
the boiler (or in an adjacent, communicating room) can, in
certain conditions, adversely affect the safe operation of the
boiler. Where such a fan is already fitted (or if it is intended to
fit an extractor fan after installation of the appliance) the advice
of the Gas Region should be obtained.
Tests for spillage of products from the draught diverter when
the extractor fan is running and all doors and windows are shut
should be carried out after installation. If spillage is detected,
the area of permanent ventilation must be increased.
8
Air vent free area cm
2
202
247
304
Boiler room Enclosure
4 10
2 5
GENERAL
CHIMNEY SYSTEM
To ensure the safe and satisfactory operation of the boiler the
chimney system (which may be common or individual, in the
case of twin or multiple boiler installations) must be capable of
the complete evacuation of combustion products at all times.
The effective height of the chimney terminal(s) above the boiler
outlet(s) must ensure sufficient buoyancy to overcome the
resistance of the bends, tees and runs of the flue pipe involved
and shall terminate in a down draught free zone. The number of
bends and lengths of horizontal flue pipe used should be kept to
a minimum in order to reduce gas flow resistance.
Compliance with the recommendations made in BS.6644,
IGE UP/10 Installation of Gas Appliances in Industrial and
Commercial Premises and the Third Edition of the 1956 Clean
Air Act Memorandum' should be strictly observed where
applicable.
The chimney design should avoid the formation of excessive
quantities of condensate. For this reason it is recommended
that all chimneys are insulated and lined. In the case of brick or
similar structures a stainless steel rigid or flexible flue liner
(grade 304/316) may be used in conjunction with a 50 mm
(minimum) thick layer of vemiculite or perlite granules between
the liner and the inner skin of the chimney body. Liners should
be sealed at both top and bottom.
As the Concord CXA/H range of boilers is supplied complete
with an integral draught diverter, a diverter MUST NOT be fitted
within the chimney system.
Drainage points positioned at the bottom of all vertical chimney
sections should be provided. Drain pipes should be no less
than 25 mm I.D., manufactured from acid condensate resistant
material such as stainless steel and be positioned so that pipe
runs and discharge points are not subject to the effects of frost
and that flue gases cannot leak into the boiler room.
Care should be taken to ensure the specification of the chimney
is suitable for the application by reference to the manufacturers
literature. Caradon Ideal Limited can offer advice on the design
of suitable chimney systems.
GAS SUPPLY
If there is any doubt regarding the capacity of the gas meter, the
available gas pressure, the adequacy of existing service pipes
or the size required for new service pipes then the advice of the
gas region should be requested.
Installation pipework should be fitted and tested for gas
soundness in accordance with BS. 6891;
IGE-UP-1 for small installations
IGE-UP-2 for large installations.
The local gas region must be consulted if it is necessary to
employ a gas pressure booster.
ELECTRICAL SUPPLY
WARNING. This appliance must be efficiently earthed.
A 230 V - 50 Hz mains supply is required, fused at 5 amps.
Wiring external to the appliance MUST be in accordance with the
I.E.E. (BS. 7671) Wiring Regulations and any local regulations
which apply.
For details of connections refer to Frame 14.
Concord CXA/H
- Installation and Servicing