NuAire MRXBOX95-WM1 User manual

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95-WM1 (Standard Unit)
MRXBOX95-WM1 -OH (Opposite Hand Unit)
MRXBOX95AB-WM1 (Standard Unit)
MRXBOX95AB-WM1-OH (Opposite Hand Unit)
Mechanical Ventilation Units with Heat Recovery for Wall Mounting
Installation Manual
EMC Directive
2014/30/EU
LVD Directive
2014/35/EU
1.0 SAFETY INFORMATION
• The provision of the electrical supply and the connection of the unit to the electrical supply
must be carried out by a qualified electrician in accordance with latest edition of the wiring
regulations.
• Isolate from power supply before removing any covers. During installation / maintenance ensure
all covers are fitted before switching on the mains supply.
• 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.
• This unit must be earthed.
• 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.
• If the supply cord is damaged, it must be replaced by the manufacturer, its service agent or
similarly qualified persons in order to avoid a hazard. The replacement cord must be of the same
technical specification as the original cord or greater.
• 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.
• This appliance should not be used by children or persons with reduced physical, sensory or
mental capabilities or lack of experience and knowledge, unless they have been given supervision
or instruction concerning the safe use of the appliance by a person responsible for their safety.
Children shall not play with the appliance. Cleaning and user maintenance shall not be carried
out by children.
1.1 Hazard Symbols
REFER TO INSTRUCTION MANUAL
Read and understand the installation and maintenance manual before installing,
operating or maintaining this product.
1.2 Important Information
This manual contains important information on the safe and
appropriate assembly, transport, commissioning, operation,
maintenance, disassembly and simple troubleshooting of the product.
While the product has been manufactured according to the accepted
rules of current technology, there is still a danger of personal injury or
damage to equipment if the following general safety instructions and
the warnings contained in these instructions are not complied with.
•Read these instructions completely and thoroughly before
working with the product.
•Keep these instructions in a location where they are accessible
to all users at all times.
•Always include the operating instructions when you pass the
product on to third parties.
1.3 Personal Protective Equipment
The following minimum Personal Protective Equipment (PPE) is
recommended when interacting with Nuaire product:
•Protective Steel Toed Shoes - when handling heavy objects.
•Full Finger Gloves (Marigold PU800 or equivalent) - when
handling sheet metal components.
•Semi Fingerless Gloves (Marigold PU3000 3DO or equivalent)
- when conducting light work on the unit requiring tactile
dexterity.
•Safety Glasses - when conducting any cleaning/cutting operation
or exchanging filters.
•Reusable Half Mask Respirators - when replacing filters which
have been in contact with normal room or environmental air.
Nuaire would always recommend a site specific risk assessment by a
competent person to determine if any additional PPE is required.

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
2.0 INTRODUCTION
The WM1 wall mounted range of units is designed to provide
mechanical supply and extract ventilation with heat recovery.
The unit is fitted with two independent fans. Each fan has full speed
control for background and boost ventilation rates. To recover heat
from the extract air the heat exchanger block is utilised. The heat
exchanger can recover up to 95% of the normally wasted heat.
If the unit has integral automatic summer bypass (AB models
only). The bypass damper shall open automatically via a wax actuator
allowing the air to bypass the heat exchanger to deliver fresh filtered air
during the warmer months.
Extract air
from house
Intake air
Exhaust air
from outside
to outside
from house
to house
Supply air
Intake air
from outside
Extract air
from house
Supply air
to house Exhaust air
from house
to outside
1 Airflow Through unit (Standard Unit)
Extract air
from house
Intake air
Exhaust air
from outside
to outside
from house
to house
Supply air
Intake air
from outside
Extract air
from house
Supply air
to house Exhaust air
from house
to outside
2 Airflow Through OH unit (Opposite Hand Unit)
3.0 MECHANICAL INSTALLATION
Installation must be completed by competent persons, in accordance
with good industry practice and should conform to all governing and
statutory bodies i.e. IEE, CIBSE, etc.
A clear working space is required around the installed unit to allow the
cover to be removed and provide sufficient access for maintenance
such as filter change.
Allow a minimum of 280mm in front of the MVHR unit for access.
The fan 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 wall.
The unit must remain switched on at all times to maintain
ventilation within the dwelling. Turning the unit off will cause long
term damage to the unit and building fabric.
These units are not recommended for loft mounting.
3.1 Wall Mounting
The unit is designed for wall mounting, only on a solid wall. A
gypsum block or stud/plasterboard wall will not suffice.
1. One part of the mounting bracket (supplied) should be offered up
to the wall, ensuring it’s located horizontally. Mark the fixing points
through the pre drilled holes in the bracket and install with screws
(by others), whilst ensuring the interlock side is at the top (Figure 3).
2. Install the unit on the wall by ensuring the bracket fixed to the rear
of the unit interlocks over the wall mounted bracket (Figure 4).
Care must be taken to ensure the unit is installed true in all 3
dimensions. Failure to do so may result in overflow from the
internal condensation drip tray.
3 Wall Mounting Bracket
4 Mounting Unit Onto Bracket
3.1.1 Option 1 - Solid Wall
The MVHR unit fixed to a solid wall construction using the
mounting bracket provided.
Ducting in the
ceiling void.
Side view of unit
mounted on the
block wall in a
cupboard.
MVHR-DRAIN
Condensate drain,
uninsulated drain
pipe with min 5 o
fall running to SVP.
Valve in ceiling.
5 Solid Wall Mounted Unit Installation
3.1.2 Option 2 - Non-Solid Wall
If it is not practical to use a solid wall, the MVHR unit should be
fixed to a stud partition with a 25mm minimum thickness MDF
panel solidly fixed behind the plasterboard.
If fixing to a stud wall the MDF panel should extend, width wise, over a
minimum of 3 vertical studs with centres of no more than 400mm. Add
additional vertical supports if necessary.
Height wise, ideally, the MDF panel should extend from floor to ceiling
but as a minimum should be a least 2m high.
Fix the mounting bracket to the wall (Figure 3) and use the wall
mounted bracket to mount the unit on (Figure 4).

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
To SVP
“T” piece
MVHR Drain
To unit
To CONTRAP
9 "T" Piece CONTRAP & MVHR Drain Connection
3.3 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 sq. mm.
3.4 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 Ø or 204 x 60mm rectangular ducting should be used.
Refer to dwelling design drawing for further information (Figures 11 &
12).
Ducting joints must be sealed with silicone type sealant and shall be
adequately and reliably fixed to the appliance.
3.5 Ventilation Flow Rates
ADF 2010 - Extract Ventilation Rates
Room Minimum High rate Minimum 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
6 Non-Solid Wall Mounted Unit Installation
Ducting in the
ceiling void.
mounted in a
Side view of unit
a stud partition
cupboard fixed to
with the 25mm
MDF fixed behind
MVHR-DRAIN
the plasterboard.
Condensate drain,
uninsulated drain
pipe with min 5 o
fall running to SVP.
Valve in ceiling.
3.2 Condensate Drain
The condensate must be discharged under a water level in a U-trap
drainpipe or an alternative drain method which acts as an airlock. This
condensate discharge connection is suitable for 21.5mm Ø overflow
pipe. Solvent cement should be used to make the joint.
If using a U-trap please ensure the U-trap has been filled to a suitable
level of water to avoid any air locks. If the condensation pipe (minimum
5° drop) is fitted in an unheated space the pipe should be in insulated
to prevent freezing.
An MVHR-DRAIN is recommended for use as the primary
condensate take-off (Figures 7 and 8), with a minimum 5° fall
running to SVP
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.
Min 5o Drop
7 Condensate Trap Installation
Condensate pipe connection to
unit and a typical example of a
“U” trap drainpipe (Standard
configuration only).
Collar
8 MVHR-DRAIN Installation
Condensate drain,
uninsulated drain pipe with
min 5° fall running to SVP.

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
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.
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.
3.6 ADF 2010 Ventilation Calculations Design of MVHR
Systems
The MVHR system has been sized for the winter period. Additional
ventilation may be required during the warmer months and it has
been assumed that the provisions for purge ventilation (e.g. openable
windows) could be used.
Step 1: For any design air permeability, determine the whole dwelling
ventilation supply rate from Whole Dwelling Ventilation Rates table.
As an alternative where the design air permeability is intended to be
more than (>) 5m3/(h.m2) 50 Pa, allow for infiltration for all dwelling
types by subtracting from the whole dwelling ventilation supply rate
from Whole Dwelling Ventilation Rates table; 0.04 x gross internal
volume of the dwelling heated space (m3).
Step 2: Calculate the whole dwelling extract ventilation rate by
summing the individual room rates for ‘minimum high rate’ from ADF
2010 - Extract Ventilation Rates table.
(For sanitary accommodation only, as an alternative, the purge
ventilation provisions given in ADF 2010 can be used where security is
not an issue. In this case ‘minimum high extract rate’ for the sanitary
accommodation should be omitted from the step 2 calculation).
Step 3: The required airflow rates are as follows:
•The maximum whole dwelling extract ventilation rate (e.g. boost)
should be at least the greater of step 1 and step 2. Note that the
maximum individual room extract rate should be at least those
given in ADF 2010 - Extract Ventilation Rates table.
•The minimum air supply rate should be at least the whole building
ventilation rate found in step 1.
For Scotland refer to BRE Digest 398.
For further information refer to “Domestic Ventilation Compliance
Guide” www.planningportal.gov.uk/buildingregulations/approved
documents/partl/compliance
3.6.1 Pre Commissioning MRXBOX MVHR Units
MRXBOX units are designed to ventilate the whole dwelling and must
not be used during site construction or the clean-up period. Cement
and plaster dust can be abrasive and can affect fan performance
and reliability. Please ensure that the filters are checked prior to
commissioning to ensure there is no build-up of dust or debris.
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 the air valves or cover up the air valves to
prevent condensation forming in the ductwork and the MRXBOX unit
due to natural migration of warm air.
3.7 Dimensions (mm)
10 Unit Dimensions
603
468
Mounting
Bracket
288
Side ViewFront View
Top View
130 79
100
400
125
79 400 124
79
288

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
3.8 Ducting Arrangements - Standard Unit Configuration
3.8.1 Circular Ducting
11 Typical Circular Ducting Arrangement For Wall Mounted Units
Air supply
to lounge
in ceilings.
via Air Valve
Extract air
from
kitchen/
bathroom
in ceilings.
via Air Valve
Exhaust air from
kitchen/bathroom to
outside via louvre grille.
Minimum distance as specified
in building regulations.
Intake air
from outside
via louvre grille.
All duct between MVHR
unit and atmosphere to
be insulated*.
*Insulated
supply duct.
Top of ceiling void.
Air supply to
bedrooms
in ceilings.
via Air Valve
mounted unit.
Nuaire wall
MVHR-DRAIN
Condensate drain, uninsulated
drain pipe with min 5ofall running to SVP.
*Insulated
extract duct.
3.8.2 Rectangular Ducting
12 Typical Rectangular Ducting Arrangement For Wall Mounted Units
Exhaust air from
kitchen/bathroom to
outside via air brick.
Minimum distance as specified
in building regulations.
Intake air
from outside
via air brick.
All duct between MVHR
unit and atmosphere to
be insulated*. *Insulated
supply duct.
Air supply
to lounge
in ceilings.
Extract
via Air Valve air from
kitchen/
bathroom
in ceilings.
via Air Valve
Air supply
to bedrooms
in ceilings.
via Air Valve
Top of ceiling void.
mounted unit.
Nuaire wall
MVHR-DRAIN
Condensate drain, uninsulated
drain pipe with min 5ofall running to SVP.
*Insulated
extract duct.
New
ALSO FROM NUAIRE -
range of thermal ducting,
an all-in-one insulated ducting system
(see installation document 671780)

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
4.0 ELECTRICAL INSTALLATION
All mains wiring must be in accordance with the current I.E.E.
Regulations or the appropriate standards (including mains power
supply connected to a fixed wiring installation, via a fused isolator).
Ensure that the mains supply (Voltage, Frequency and Phase) complies
with the rating label.
For good EMC engineering practice, any sensor cables or switched
live cables should not be placed within 50mm of other cables or on
the same metal cable tray as other cables.
The electrical connection of the unit must be carried out by a qualified
electrician. The unit is supplied with a flexible cord for connection to
the mains supply.
This unit must be earthed.
If the supply cord is damaged, it must be replaced by the
manufacturer, its service agent or similarly qualified persons in
order to avoid a hazard. The replacement cord must be of the same
technical specification as the original cord or greater.
4.1 Electrical Information
Voltage: 240V 1ph 50Hz
Consumption: 1.2 Amp
4.2 Optional Connections
Ecosmart Control (Figure 13) The IDC plug-in connectors are provided
for the connection of compatible sensors.
4.2.1 PCB
TEMP
Connection to
Remote Fail
Indicator Ref:
MRXBOX95LH-RFI
(Optional)
24V 0V SW
FAN 1
FAN 2
Internal Wiring
Connection to
Ecosmart
Sensors
Run-on Trickle Boost Trickle Boost
ECOSMART NET
Wiring is for
reference
purposes only,
connections
shown are
factory fitted.
The unit is
pre-wired with a
2 metre fly lead.
13 PCB Details
4.3 Wiring Diagrams
Wiring is for reference purposes only, connections shown in Figure 13 are factory fitted. The unit is pre-wired with a 2 metre fly lead.
4.3.1 Unit Serving Kitchen and Bathroom
14 Wiring Diagram - Unit Serving Kitchen And Bathroom
3A Fuse
(BS 1362)
MAINS
230V
50Hz
Light
Room
Light
Switch
(Double
Pole)
N
L
3 Pole
Isolator
Kitchen Switch
Blue
Brown
Black
Supply Cord
From Unit
Green / Yellow
4.3.2 Unit Serving Kitchen and 2 Bathrooms
15 Wiring Diagram - Unit Serving Kitchen And Two Bathrooms
3A Fuse
(BS 1362)
MAINS
230V
50Hz
Room
Lights
Light
Switches
(Double
Pole)
N
L
3 Pole
Isolator
Kitchen Switch
Blue
Green / Yellow
Brown
Black
Supply Cord
From Unit

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
5.0 COMMISSIONING
The filters fitted inside the unit are protected with a plastic film.
Prior to commissioning remove the covers (Figures 18 & 19), take
off the film and replace.
1. For the required air flow rates please refer to the design specification
for the property, Section 3.6, or refer to building regulations ADF
2010.
2. The unit is supplied with independent control for both normal and
boost airflows (Figure 16).
3. Correct commissioning is essential to ensure the ventilation air flow
rates are met. It also ensures the unit is not over ventilating and
causing excessive power consumption.
4. Commissioning should be carried out in accordance with building
regulations document “Domestic ventilation compliance guide”.
www.planningportal.gov.uk/building regulations/approved
documents/partf/associated. A calibrated moving vane
anemometer and hood will be required to carry out commissioning.
5. Adjustment valves should be locked in place to prevent further
adjustment.
6. Once commissioned the home owner / tenant should be informed
that the unit should not be adjusted as it will have a detrimental
effect on the indoor air quality and could result in condensation and
mould growth. The clear panel covering the control has an adhesive
panel which should be exposed and sealed post commissioning to
prevent tampering.
7. Speed 1 is limited to never exceed speed 2, when commissioning
speed 2 should always be set first.
Ext
F
r
a
a
n
ct Su
F
p
a
p
n
ly
Runon Trickle Boost Trickle Boost
Extract
Fan
Supply
Fan
For commissioning:
refer to user manual
Ventilation Controls
Post commissioning remove
adhesive backing under
this section
Run on Trickle Boost Trickle Boost Power Fan
Failure
16 Unit Control On Front Panel (Standard Configuration Only)
5.1 Thermal Bypass (Non AB models)
In the event of excessive outside temperatures, and to help prevent
over-heating, the supply fan will automatically reduce to a trickle
speed. Under these circumstances additional ventilation measures may
be required e.g. open windows or trickle vents (if fitted).
5.2 Status Indication
The status of the unit is indicated by a series of LED’s on the front cover.
The variants are listed below.
The display on the unit control panel will not indicate when a
higher speed setting has been triggered by an external source, such
as an ES-PIR2 etc.
17 Unit Control On Front Panel (Standard Configuration Only)
Summer Bypass
(AB Units Only)
Normal Mode
Boost
Supply Fan Fault
Extract Fan Fault
Frost Protection
Filter Change
6.0 MAINTENANCE
It is important that maintenance checks are recorded and that the
schedule is always adhered to, in all cases, the previous report should
be referred to.
6.1 Filters
Filters are to be inspected every 6 months and replaced every 12
months (or sooner if required). Failure to do so may impair the
performance and energy efficiency of this unit. A flashing LED
(Section 5.2) will indicate that a filter change is required. This indication
repeats every 12 months and will turn off automatically after 5 Days.
Remove the filter covers on the front panel of the unit by gripping the
two circular tabs either end of the filter covers and pulling away from
the unit. The filter can now be extracted by pulling the black removal
loop on the front edge of the filter. Once the filters have been inspected
return or replace them as necessary.
18 Removing Filter Covers
Filter covers
Filter being
removed
Filter cover
19 Removing Filters
Filter covers
Filter being
removed
Filter cover

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28. 10. 20. Document Number 671684Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA |nuaire.co.uk
MRXBOX95(AB)-WM1Installation Manual
7.0 WARRANTY
The 5 year warranty starts from the day of delivery and includes parts
and labour for the first year. The remaining period covers replacement
parts only.
This warranty is void if the equipment is modified without
authorisation, is incorrectly applied, misused, disassembled, or not
installed, commissioned and maintained in accordance with the details
contained in this manual and general good practice.
The product warranty applies to the UK mainland and in accordance
with Clause 14 of our Conditions of Sale. Customers purchasing from
outside of the UK should contact Nuaire International Sales office for
further details.
Failure to maintain the unit as recommended will invalidate the
warranty.
8.0 END-OF-LIFE AND RECYCLING
Where possible Nuaire use components which can be largely recycled
when the product reaches its end-of-life:
•Fans, motors, controls, actuators, cabling and other electrical
components can be segregated into WEEE recycling streams.
•Sheet metal parts, aluminium extrusion, heating/cooling coils and
other metallic items can be segregated and fully recycled.
•EPP, plastic ducting, nylon corner pieces, plastic heat exchangers,
packaging material and other plastic components can be
segregated into mixed plastic and widely recycled.
•Cardboard packaging, wood, and other paper components can be
largely recycled or fully processed in energy from waste centres.
•Filter Disposal: Cardboard framed filters should be fully processed
in energy from waste centres, contact your local civic amenity site
/ household waste recycling centre regarding metal / wire framed
filters.
•Remaining Items can be further segregated and processed in
accordance with the zero waste hierarchy. Please call After Sales
Support for further information on items not listed above.
Ensure that Nuaire product is made safe from any electrical / water
/ refrigerant supplies before dismantling commences. This work
should only be undertaken by a qualified person in accordance with
local authority regulations and guidelines, taking into account all
site based risks.
9.0 AFTER SALES AND REPLACEMENT PARTS
For technical assistance or further product information, including spare
parts and replacement components, please contact the After Sales
Department.
If ordering spares please quote the serial number of the unit together
with the part number, if the part number is not known please give a full
description of the part required. The serial number will be found on the
identification plate attached to the unit casing.
Telephone [phone]
[e-mail]
Technical or commercial considerations may, from time to time,
make it necessary to alter the design, performance and dimensions
of equipment and the right is reserved to make such changes without
prior notice.