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17. 11. 21. Document Number 671861
Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk
MRXBOXAB-ECO3-AE(OH)SW & MRXBOXAB-ECO5-AE(OH)(SC/SW)
Installation Manual
5.0 COMMISSIONING
The filters fitted inside the unit are protected with a plastic film.
Prior to commissioning remove the covers (Figure 20), take off the
film and replace.
1. For the required air flow rates please refer to the design specification
for the property, follow 2.4, or refer to building regulations ADF
2010.
2. The unit is supplied with independent control for both normal and
boost airflows (Figure 18).
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.
18
Unit Control On Front Panel
(Standard Configuration Only)
+
-
Post commissioning remove
adhesive backing and seal
Power Fan
Failure
+
-
Ventilation Controls
- +
+
- +
-
Speed 1
- +
Speed 2
Speed 3
Supply Extract Supply Extract Supply Extract
Humidity adjustment
5.1 Humidity Adjustment
This product contains an internal humidity sensor fitted into the air-
flow extracting from the wet rooms. When the unit senses that the
humidity exceeds the set point the unit will boost to that set by the
commissioned boost speed. The set point can be found on the front
of the unit (Figure 18) and is at its least sensitive when turned fully
clockwise. Note that the sensor is measuring humidity from all the wet
rooms at the same time and should not be relied on to solely boost the
unit. Additional switch should be used local to the wet rooms (Section
4.2).
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.
19
Unit Control On Front Panel
(Standard Configuration Only)
HX Bypass
(AB units only)
Speed 1
Speed 2
Speed 3
Supply Fan Fault
Extract Fan Fault
Frost Protection
Filter Change
5.3 Integral Automatic HX Bypass
Intake and extract temperatures are monitored at the point the
airflows enter the unit, if the range falls within the set parameters the
bypass damper is opened automatically to target an indoor comfort
temperature all year round.
The extract temperature is an average from all wet rooms. If this
exceeds 25°C the unit may go into bypass depending on outside
temperatures.
5.4 Summer / Winter Switch
When the switch position is set to Summer the integral automatic
summer bypass is fully operational, in the alternative Winter position
the HX bypass is disabled to ensure the unit is constantly in heat
recovery mode.
5.5 Speed 3 Operation (SW Units Only)
Speed 3 will be non-operational if the intake temperature is greater
than the extract temperature.
5.6 Frost Protection
In the event of the intake air temperature at the unit dropping below
the predetermined set point (-5°C as standard) the supply fan will
reduce to minimum speed, once the temperature rises above the set
point the fan will return to its commissioned speed.
Frost protection will only activate after ten days of continuous run
time. If commissioning of the unit is outside of this time frame please
notify the after sales department prior to site visit.
