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nuaire.co.uk
029 2085 8400
04. 11. 19. Leaflet Number 671859
Installation and Maintenance
MRXBOXAB-ECO2-AESW Mechanical Ventilation Unit with Heat Recovery
2.6 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 are to have a minimum free area of 12,250 mm
2
.
2.7 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.
If the enclosure is to be used in conjunction with an ancillary
distribution box (MRXBOX-DB2) refer to additional assembly
instructions supplied with the MRXBOX-DB2 as requirements will
differ.
Otherwise fit 4x 125mm diameter plastic spigots with the self-tapping
screws supplied to the spigot fixings plates found on the top panel of
the enclosure, a bead of silicone should be applied to the groove of
spigot fixing plate to prevent leakage (see fig. 3).
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 125mm diameter or 220 x 90mm rectangular ducting should be
used. (Refer to dwelling design drawing, figure 10a and 10b 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.
2.8 Ventilation Flow Rates
Table 1. ADF 2010 - Extract ventilation rates.
Table 2. Whole dwelling ventilation rates.
Notes:
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.
IMPORTANT
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.
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
Number of bedrooms in dwelling
1
2
3
4
5
Whole dwelling
ventilation rate
(l/s)
1,2
13
17
21
25
29
