6
400-600mm Joist Dimensions with Unit Clearance Heights
E. DIFFUSER GRILLE:
IMPORTANT: PureAir Home FD models are provided with a different diffuser.
Please note: You cannot fit the heater unit to the diffuser on
“FD” models.
The diffuser must be carefully sited to ensure the maximum effectiveness of the system. It should be fitted in the
ceiling of a common area, ideally above the landing so that the incoming air can reach all the rooms.
Cut the flexible ducting to a suitable length, where possible stretch the ducting to its maximum extent and ensure that
there is one continuous smooth bend to the diffuser. The ducting
must
remain a minimum of 1m in length.
Remove the loft insulation from the location of the diffuser and cut a 240-260mm dia hole in the ceiling.
Ensure the four locking tabs are folded in and then push the spigot in to the hole. Holding the diffuser in place; screw
the four screws until the locking tabs are holding the diffuser tight against the ceiling (Fig.5).
It is important not to
over tighten these screws as this may warp the diffuser.
Fit the free end of the flexible ducting to the diffuser spigot using the worm drive clip supplied.
The diffuser should not be situated within 1m of a smoke detector, however if this is not possible the Lo-
Carbon PureAir Home has provisions to blank off the airflow for up to two quadrants of the diffuser. Two
blanking plates are provided; these should be pushed on to the support struts inside the diffuser as
required. This should be done before the diffuser is installed in the ceiling as when the screws are tightened
down the plates can no longer be removed. See Fig.6, showing blocking off opposing quadrants, note any 1
or pair of quadrants can be blocked off as necessary for the install. These block off plates can also be used
to ensure the supply air is spread across a room rather than directed at close by walls.
Blanking off one side reduces the flow by about 6%, but blanking off two sides reduces the flow by about 20% and so
if two sides are blanked off then you should consider increasing the fan speed to maintain the appropriate airflow.
Fig. 5.
Fig. 6.