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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.

This appliance is not intended for use by persons 

(including children) with reduced physical, sensory or

mental capabilities, or lack of experience and knowledge,

unless they have been given supervision or instruction

concerning the use of the appliance by a person for their

safety. Children should be supervised so that they do not

play with the appliance.

MRXBOX95-WM2

Mechanical Ventilation Unit with Heat Recovery 

for Wall Mounting

Installation and Maintenance

1.0 Introduction

MRXBOX95-WM2 wall mounted unit 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 90% of the

normally wasted heat.

2.0 Installation

Installation must be carried out by competent personnel in

accordance with the appropriate authority and conforming 

to all statutory governing regulations. All mains wiring must 

be in accordance with the current I.E.E. Regulations, or the

appropriate standards. Ensure that the mains supply 

(Voltage, Frequency and Phase) complies with the rating label. 

Please note 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.

Please allow a minimum of 350mm in front of the unit.

The fan must be installed indoors, on a suitable wall away

from direct sources of frost, heat, water spray or moisture

generation. For a vibration-free result the unit must be 

mounted to a solid wall.

The unit is designed for wall mounting only via a patress.

1. One part of the mounting bracket 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), ensuring the interlock side 

is at the top, fig. 2. 

2. Fix the remaining part of the bracket to the unit using the 

M5 screws ensuring the interlock side is at the bottom, fig.3a.

3. Install the unit on the wall by ensuring the bracket on the 

unit interlocks over the wall mounted bracket (fig. 3b).

Note: 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.

Nuaire Limited

Western Industrial Estate  Caerphilly  United Kingdom  CF83 1NA  

T: 029 2085 8400  F: 029 2085 8444  E: info@nuaire.co.uk  W: www.nuaire.co.uk

1

08. 05. 14. Leaflet Number 671588

Extract air 

from house

Intake air 

from outside

Exhaust air 

from house

to outside

Supply air 

to house

 

Figure 1. Airflow through unit.

The EMC Directive 

2004/108/EC  

The Low Voltage 

Directive 

2006/95/EC

Figure 3a. Fixing the mounting

bracket to the rear of unit.

 

 

 

 

 

 

 

 

 

 

 

 

 

Pre-fitted

support feet

Bracket

Figure 3b. Mounting the unit

on the wall mounted bracket.

Figure 2. Fixing the mounting bracket to the wall via a patress.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

125mm dia. 

ducting in 

ceiling void.

First floor ceiling.

Side view of unit 

mounted on the

wall in a cupboard.

(Note: The unit must 

be fixed to a suitable 

patress in upright 

position as shown to 

comply with safety 

regulations).

MVHR-DRAIN

Condensate drain,

uninsulated drain 

pipe with 10

o

 fall 

running to SVP.

Supply air valve in ceiling.

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

   

 

 

 

 

 

 

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 4. Typical example of a cupboard mounted unit on a patress

using the bracket.

Summary of Contents for MRXBOX95-WM2

Page 1: ...le wall away from direct sources of frost heat water spray or moisture generation For a vibration free result the unit must be mounted to a solid wall The unit is designed for wall mounting only via a patress 1 One part of the mounting bracket 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 scr...

Page 2: ... minimum A minimum distance of 200mm 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 7a and 7b on page 4 for further information Ducting joints must be sealed with silicone type sealant and shall be adequately and reliably fixed to the appliance 2 4 Ventilation flow rates ...

Page 3: ...east the greater of step 1 and step 2 Note that the maximum individual room extract rate should be at least those given in table 1 for minimum high rate n the minimum air supply rate should be at least the whole building ventilation rate found in step 1 2 7 ADF 2010 Ventilation calculations Design of MVHR systems The MVHR system has been sized for the winter period Additional ventilation may be re...

Page 4: ...um 300mm Air supply to lounge via Air Valve Part no VS125 in ceilings Extract air from kitchen bathroom via Air Valve Part no VS125 in ceilings Air supply to bedrooms via Air Valve Part no VS125 in ceilings Top of ceiling void Top of ceiling void Nuaire MRXBOX95 WM2 wall mounted unit on a patress Air supply to bedrooms via Air Valve Part no VS125 in ceilings Nuaire MRXBOX95 WM2 wall mounted unit o...

Page 5: ...olator 3 Pole isolator Kitchen switch Kitchen switch Blue Brown Black Optional summer boost switch Supply cord from unit Green yellow Blue Brown Black Supply cord from unit Optional summer boost switch Grey Grey Green yellow Unit serving kitchen and bathroom Unit serving kitchen and two bathrooms Figure 9 Figure 10 SWL2 L SWL1 L N CN7 EXTRACT CN6 SUPPLY BLU WHI YEL RED SUPPLY BYPASS SUPPLY FAN EXT...

Page 6: ...e removed post commissioning to prevent tampering 6 1 Summertime boost facility The unit has to ability to override both the trickle and boost speeds to operate the fan to maximum airflow See wiring diagram for details of operating this facility 7 0 Status Indication The status of the unit is indicated by a series of LED s on the front cover The varients are listed below 8 0 Maintenance Cleaning W...

Page 7: ...ange speed This is normal and will have no adverse effect on the fan The speed will return to normal once the interference has subsided 5 0 INSTALLATION REQUIREMENTS In addition to the particular requirements given for the individual product the following general requirements should be noted 5 1 Where access to any part of equipment which moves or can become electrically live are not prevented by ...

Page 8: ...CF83 1NA T 029 2085 8400 F 029 2085 8444 E info nuaire co uk W www nuaire co uk 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 ...

Page 9: ...lings assessed under The Building Regulations 2010 specifically SAP 2009 and Approved Documents L and F Completion of this document is therefore only required for dwellings assessed by SAP 2005 Customer Details Customer Name Address Telephone Number Date of Installation Name of Lead Contractor Design Project Number It should be noted that this guidance is not intended to replace product manufactur...

Page 10: ...or to overcome particular obstructions If flexible ducting has been used has it been pulled taut to minimise system resistance Has the number of duct bends been minimised to ensure adequate air flow and least resistance Bends should have a minimum radius at least the same as the diameter of the ducting used Refer to Figure 1 if using flexible ducting Have the fans and ducting placed in unheated vo...

Page 11: ...ry unit been fixed to a stable element of the building fabric e g wall or floor using manufacturer recommended supplied fixing brackets Has the condensation drain been fitted and the pipe insulated Have approved acoustic anti vibration mountings been used Note Special attention is needed to avoid transmission and stress to duct joints Has the unit been installed in a position that will permit acce...

Page 12: ... or N A Has the rating label been verified to establish suitability for the installation strategy and whether an earth is required e g voltage class I or II product status Has a local isolator been provided to enable the unit to be isolated for maintenance purposes Has the unit been fused in accordance with its power rating SECTION 2 COMMISSIONING GUIDANCE ...

Page 13: ...ution grilles been locked where possible to minimise unapproved occupant adjustment Figure 3 Ensure all external and internal windows and doors are closed Set fan speed using manufacturer data table Set normal daytime air flow on extract points starting at location furthest from unit Set normal daytime air flow on input points starting at location furthest from unit Step 1 Step 2 Step 3 Step 4 Ste...

Page 14: ...he customer been advised that opening windows is not recommended during normal use in order to ensure the energy efficient operation and performance of the balanced system Has the customer been advised not to seal natural air flows from room to room e g avoid door seals and thick pile carpets Has the customer been advised not to alter settings post commissioning Has the customer been advised to cl...

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