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nuaire.co.uk
029 2085 8400
30. 05. 19. Document Number 671924
Installation and Maintenance
MEV-X
- Continuous Extract Unit
4.0 DIMENSIONS (mm)
4.1 Unit Dimensions
The unit is not fitted with a back-draught shutter or filter as
standard. These should be integrated into the system design where
appropriate and can be purchased from Nuaire if required. If
extracting from a dwelling it is advised the incoming air to the unit
is filtered to minimum grade of G2.
It is recommended that rigid ducting 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.
If used to supply fresh air from outside the heated envelope of the
dwelling, the duct should be insulated with material having a thermal
resistance of >0.625m2 K/w, in order to prevent condensation on the
exterior of the duct to the unit.
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 200mm between the appliance and any bends
in ductwork is recommended. Ideally 200mm diameter or 220 x 90mm
rectangular ducting should be used.
Ducting joints must be sealed with silicone type sealant and shall be
adequately and reliably fixed to the appliance.
3.2 Pre-Commissioning
The unit must not be used during site construction or the clean-up
period as cement and plaster dust can be abrasive which may affect fan
performance and reliability.
While the property is drying out, very high moisture levels are likely
to occur. Therefore it is advisable that if the installation and building
works are complete the unit is left running. If the building works are not
complete, please close or cover the air valves to prevent condensation
forming in the ductwork and unit due to natural migration of warm air.
Airflow
151
150
70
81
590
560
131
230
303
20
220
230
10
25
165
40
35
Mains Entry (Allow 20mm Clearance)
Figure 1. Unit Dimensions
3.0 INSTALLATION
The provision of the electrical supply and the connection of the unit
to the mains must be carried out by a qualified electrician. All-pole
disconnection from the mains as shown in the wiring diagram must be
incorporated within the fixed wiring and shall have a minimum contact
separation of 3mm in accordance with latest edition of the wiring
regulations. Ensure that the mains supply (Voltage, Frequency and
Phase) complies with the rating label.
Please note sufficient access and a clear working space around
the unit is required to allow access for commissioning and also
for maintenance of key components, please allow a minimum of
110mm from the access panels (Figure 1). An additional 20mm will
be required at the mains entry point to allow cable routing, this
distance will be greater if using an additional cable gland.
The unit is designed to be installed predominantly on a ceiling/slab,
the unit must not be floor mounted. If wall mounting to prevent
potential water ingress the cable entry should be on the underside
of the unit or replaced with a sealed cable gland, the unit must also
be mounted square to prevent ingress around the PCB cover.
The unit must be installed indoors, on a suitable wall away from direct
sources of frost, heat and water spray or moisture generation. For a
vibration-free result the unit must be mounted to a solid structure.
The unit can be secured in place using the four mounting holes (fixings
supplied by others) provided (Figure 2).
To ensure vibration is not transferred into the structure, it is
advised to fit a small spacer (supplied) between the unit and the
mounting surface at each fixing point.
3.1 Ducting
Ducting must be securely fixed with screws to the spigot to prevent
access to live parts. Duct runs terminating close to the fan must be
adequately protected by suitable guards.
Precautions must be taken to avoid the back-flow of gases into the
room from the open flue of gas or other fuel-burning appliances.
