Cougar Inset Manual (Ref No: MI0405 V1)
9 Cast Tec Ltd
DOWN DRAUGHTS
However well designed constructed and
positioned, the satisfactory performance of the
flue can be adversely affected by down
draught caused by nearby hills, adjacent tall
buildings or trees. These can deflect wind to
blow directly down the flue or create a zone of
low pressure over the terminal. A suitable anti-
down draught terminal or cowl will usually
effectively combat direct down blow but no
cowl is likely to prevent down draught due to a
low pressure zone. (See Fig.5)
VENTILATION AND COMBUSTION AIR
REQUIREMENTS
This appliance is rated less than 5kW,
therefore there is no mandatory requirements
for additional air unless a flue draught
stabiliser is fitted then the air requirement is
15cm
2
. However, we suggest that it is
advantageous to provide an air supply into the
room.
When calculating combustion air requirements
for this appliance use the following equation:
550mm
2
per each kW of rated output above 5
kW should be provided, where a flue draught
stabiliser is used the total free area shall be
increased by 300mm
2
for each kW of rated
output. If there is another appliance using air
fitted in the same or adjacent room, it will be
necessary to provide an additional air supply.
All materials used in the manufacture of air vents should be such that the
vent is dimensionally stable, corrosion resistant, and no provision for closure.
The effective free area of any vent should be ascertained before installation.
The effect of any grills should be allowed for when determining the effective
free area of any vent.
