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nuaire.co.uk
029 2085 8400
19. 08. 19. Leaflet Number 671858
Installation and Maintenance
MRXBOXAB-ECO-LP1SW Mechanical Ventilation Unit with Heat Recovery
ducting in
204 x 60mm
ceiling void.
in ceiling.
Side view of unit
mounted in the ceiling void.
Air valve
Figure 4. Typical side view example of a (standard unit) mounted in a
ceiling void using 204 x 60mm rectangular ducting and air valves.
2.1 Condensate Drain Installation
1. Unit comes complete with external drain pipe (21.5mm waste
pipe). Use conventional plumbing connections to link up with
U-trap or alternative drain method (Solvent cement connections
or compression fit connections are recommended). The condensate
must be discharged under a water level in a U-trap drainpipe or an
alternative drain method which acts as an airlock.
2. This condensate discharge connection is suitable for 21.5mm dia.
overflow pipe. Solvent cement should be used to make the joint.
3. If using a U-trap please ensure the U-trap has been filled to a
suitable level of water to avoid any air locks.
4. If the condensation pipe is fitted in an unheated space the pipe
should be in insulated to prevent freezing.
Nuaire recommend MVHR-DRAIN be used as the primary condensate
take-off (see fig. 5 and 6).
CORRECT
INCORRECT
Flow
Side elevation
When installed horizontally the ribs must be at the bottom to
ensure correct operation.
Figure 5. Typical side view example of a (standard unit) mounted in a
ceiling void using 204 x 60mm rectangular ducting and air valves.
Figure 6. Typical side view example of a (standard unit) mounted in a
ceiling void using 204 x 60mm rectangular ducting and air valves.
2.1.1 Fixing
Offer up the MVHR-DRAIN inlet to the threaded tail of the appliance
waste outlet or MVHR-DRAIN knuckle or running adaptor, and tighten
the threaded cap sufficiently hand-tight to provide a water-tight seal
(check that the cap screws on square and does not ‘cross-thread’).
When the screwed cap is tight, the MVHR-DRAIN body is secure.
1. Cut the pipe to length, allowing for the full compression socket
depth (using an appropriate pipe cutter, such as a Hepworth ratchet
pipe cutter).
2. Remove any ‘swarf’ from the end of the plastic pipe. Ream the
copper pipe end to remove any ‘burr’, and file if necessary to remove
any external sharp edges. Mark the socket depth on the pipe, and
check that the pipe section to be jointed is free of any surface
damage which may affect the joint seal.
3. Unscrew the cap from the MVHR-DRAIN outlet, and slide the cap
and rubber seal onto the pipe.
4. Insert the pipe end fully into the socket.
5. Slide the rubber seal and screwed cap up against the face of the
socket, and tighten the cap sufficiently hand-tight (check that the
cap is square to the body and does not ‘cross thread’). Hand tight
should be adequate to form a proper seal.
2.2 Extract/Input Areas
The unit is designed to extract air from all wet rooms e.g. bathroom,
kitchen, en-suite, utility room (with sink).
WC’s do not need to be ventilated if openable windows are fitted.
Supply air should be to all habitable rooms e.g. bedrooms and lounge.
Extract / input grilles should be adjustable valve types (not supplied).
External grilles must have a minimum free area of 12,250 mm2.
2.3 Ducting
Before commencing ducting installation reference should be made
to building regulations document “Domestic ventilation compliance
guide”. This document supports ADF2010 and details installation,
testing and commissioning of all ventilation systems.
It is recommended that rigid ducting must be used it all times. Flexible
ducting has a very high resistance and it is impossible to calculate
how much resistance will be on a system if used. If used the flexible
ducting must be kept to a minimum and should always be pulled taut.
A maximum of 300mm should be used on each leg.
To prevent condensation on the outside of the outside air inlet duct and
the air outlet duct from the MRXBOXAB-ECO-LP1, these ducts should
be insulated.
Ducting must be installed in such a way that resistance to airflow is
minimised. Bends should be kept to a minimum.
A minimum distance of 300mm between the appliance and any bends
in ductwork is recommended.
204 x 60mm rectangular ducting should be used. (Refer to dwelling
ducting design drawing, figure 6 on page 4 for further information).
Ducting joints must be sealed with silicone type sealant and needs
to be taped. Ducting shall be adequately and reliably fixed to the
appliance.
