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18. 02. 21. Document Number 671876
Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk
MRXBOXAB-ECO-LP2SW
Installation Manual
3.3 Ducting Installation
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-LP2, 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, Figures 8 & 10 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.
3.4 Ventilation Flow Rates
Any air intake terminal MUST be installed in accordance with the
appropriate regulation.
As a guide, the BS5440 series of British Standards deals with this
issue and currently states that an air intake must be at a minimum
distance of 300mm from a gas boiler balanced flue.
Installers are advised to be aware of the requirements of this
standard when installing ‘through the wall’ supply air ducting.
3.4.1 ADF 2010 - Extract Ventilation Rates
Room
Min high rate
Min low rate
Kitchen
13 l/s
Total extract rate
should be at least
the whole dwelling
ventilation rate given
in table 2.
Utility Room
8 l/s
Bathroom
8 l/s
Sanitary
Accommodation
6 l/s
3.4.2 Whole Dwelling Ventilation Rates
Number of bedrooms in dwelling
1
2
3
4
5
Whole dwelling
ventilation rate
(l/s)
1,2
13
17
21
25
29
1. In addition, the minimum ventilation rate should be no less than
0.3 l/s per m2 of internal floor area. (This includes all floors, e.g.
for a two-story building add the ground and first floor areas).
2. This is based on two occupants in the main bedroom and a single
occupant in all other bedrooms. This should be used as the default
value. If a greater level of occupancy is expected add 4 l/s per
occupant.
5
Typical Condensate Pipe Connection Using MVHR-DRAIN
Ancillary
CORRECT
INCORRECT
Flow
Side elevation
When installed horizontally the ribs must be at the bottom to
ensure correct operation.
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MVHR-DRAIN Installation
3.1.1 MVHR-DRAIN Installation
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.
•
Cut the pipe to length, allowing for the full compression socket
depth (using an appropriate pipe cutter, such as a Hepworth
ratchet pipe cutter).
•
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.
•
Unscrew the cap from the MVHR-DRAIN outlet, and slide the cap
and rubber seal onto the pipe.
•
Insert the pipe end fully into the socket.
•
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.
3.2 Extract & Supply 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 & Supply grilles should be adjustable valve types (not supplied).
External grilles must have a minimum free area of 12,250 mm
2
.
