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09. 06. 16. Leaflet Number 671684
Installation and Maintenance
The WM1 Wall Mounted Range of Units
2.3 Condensate Drain
1. 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 figure 8b and 8C.
2.4 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 to have a minimum free area of 12,250 sq mm.
2.5 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 be used at 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 unit, 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.
Ideally 150mm diameter or 204 x 60mm rectangular ducting should
be used. (Refer to dwelling design drawing, figure 9a and 9b on
page 5 for further information).
Ducting joints must be sealed with silicone type sealant and shall be
adequately and reliably fixed to the appliance.
2.6 Ventilation flow rates
Table 1.
ADF 2010 – Extract ventilation rates
Room
Min high rate
Min low rate
Kitchen
13 l/s
Utility room
8 l/s
Bathroom
8 l/s
Sanitary
accommodation
6 l/s
Table 2.
Whole dwelling ventilation rates
Number of bedrooms in dwelling
1
2
3
4
5
Whole
13
17
21
25
29
dwelling
ventilation
rate l/s
1, 2
Notes:
1,
In addition, the minimum ventilation rate be should be not less
than 0.3 l/s per m
2
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.
Figure 7a. Wet option.
Condensate pipe
connection to unit and
a typical example of
a “U” trap drainpipe.
(Standard configuration
only).
Figure 7b. MVHR-DRAIN option.
Condensate drain, uninsulated drain
pipe with min 5
o
fall running to SVP.
Min 5
o
Drop
Collar
Total extract rate should be
at least the whole dwelling
ventilation rate given in
table 2.
To SVP
“T” piece
MVHR Drain
To unit
To CONTRAP
Figure 7c.
IMPORTANT: When using a “T” Piece to connect the CONTRAP
drainage and the MVHR drain pipework the MVHR drain must always be
fitted before the “T” Piece to prevent condensate from feeding back
into the MVHR system.
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.
