Duct and Duct Connections
(refer to design drawing)
•
4 x 125mm nominal diameter spigots are provided for the connection of ducting. These are clearly marked
for correct connection of the supply and exhaust ducts.
•
Where ducting is installed in an unheated space, all of the ducts should be insulated. Where ducting is in-
stalled in a heated space, only the cold ducts should be insulated. i.e. the supply duct from outside and the
extract duct from the unit to the outside.
•
The duct layout must be designed to suit the requirements of the ventilation/recovery system and building lay
out. If the ducting passes through a fire wall/barrier, suitable fire dampers must be installed.
•
Where rigid duct is used, it should be installed using the least number of fittings to minimise air flow resist-
ance. Where possible, final connection to the grilles and unit should be made with a flexible connection.
•
Where flexible ducts are used, ensure that:
-
duct runs are kept as short as possible
-
the duct is stretched so that it is smooth and straight
-
where bends are necessary, they have large radii (ie avoid sharp bends)
-
the duct is not crushed if in a restricted area
Condensation
The unit may sometimes produce condensation which must be drained away. A 15mm dia pipe connection is
provided on this unit).
•
A 15mm dia pipe must be fitted to the pipe connection. If any part of the condensate drain is in an
unheated space it MUST be insulated with the equivalent of at least 25mm of insulating material with a
thermal conductivity of 0.04 W/(mK).
•
The pipe must drain into the normal household drainage system.
•
The drain must incorporate a wet or dry trap to prevent air penetration.
•
The unit must be tilted towards the side carryng the condensation exit point. It should be installed
horizontally with a 3º tilt towards the condensation drain used (equivalent of raising the opposite end by
approximately 25mm).
•
The drainage pipe must have a continuous fall from the unit to the drainage collection point.
Electrical Connection
WARNINg: these appliances must be earthed and all wiring must conform to current IEE Regulations and
all applicable standards and Building Regulations.
• The unit is suitable for 230v-240v, 50Hz
• The unit is supplied with a mains rated 4 core flexible cord (black, brown, grey and green/yellow), or an
external connector box
• A triple pole isolation switch with contact separation of at least 3mm must be used to connect the appli-
ance to the fixed wiring when using the Switched Live.
• Boost controls must not be located within 1 metre of a cooker or where they may be affected by
excessive heat or moisture
• Boost controls should be clearly identified and conveniently located.
• The boost switch wiring cable access is via a 12mm cable gland.
• The boost speed can be triggered by a switched live connection from a variety of external devices including:
- PIRFF (passive infra red)
*
-
DRH240 (dynamic remote humidistat)
*
-
THM (thermostat)
*
-
a light switch (if more than one light switch is used,
each one must be a double pole switch)
- a remote switch/pull cord
(
*
PIRFF, DRH240 and THM may have integral over-run timer which controls the length of time that the fan
will continue to operate at its boost speed after the boost has been switched off.)
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