NuAire MRXBOX-ECO - User Manual

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25. 01. 23. Document Number 671856

Nuaire | Western Industrial Estate | Caerphilly | CF83 1NA | nuaire.co.uk

MRXBOXAB-ECO3-SW (Standard Hand Unit)

MRXBOXAB-ECO3-OHSW (Opposite Hand Unit)

MRXBOXAB-ECO5-SC (Standard Hand Unit)

MRXBOXAB-ECO5-OHSC (Opposite Hand Unit)

MRXBOXAB-ECO5-SW (Standard Hand Unit)

MRXBOXAB-ECO5-OHSW (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 mains must be

carried out by a qualiﬁed electrician.

• 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.

• This MRXBOX unit is ﬁtted with surge protection. If RCD protection is used, a G or S type RCD is

recommended.

• 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.

• 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.

Main Page

Need help?

Do you have a question about the NuAire MRXBOX-ECO and is the answer not in the manual?

The Nuaire MRXBOXAB-ECO(3/5) series are Mechanical Ventilation Units with Heat Recovery (MVHR) designed for wall mounting in residential properties. These units provide mechanical supply and extract ventilation while recovering heat from the outgoing air, aiming to improve indoor air quality and energy efficiency.

Function Description:

The MRXBOXAB-ECO(3/5) units feature two independent fans, each with full speed control for both background and boost ventilation rates. A heat exchanger block is utilized to recover heat from the extract air, with an efficiency of up to 95% of normally wasted heat. The unit also incorporates a bypass operation, which can be disabled via a manual switch during colder months to ensure continuous heat recovery. The units are designed to extract air from wet rooms (e.g., bathrooms, kitchens, en-suites, utility rooms with sinks) and supply fresh air to habitable rooms (e.g., bedrooms, lounges).

Important Technical Specifications:

Voltage: 240V 1ph 50Hz
Earthing: The unit must be earthed.
Current Consumption:
- ECO3: 1.2 Amp
- ECO5: 2 Amp
Fuses (BS 1362):
- ECO3: 3A Fuse
- ECO5: 5A Fuse
Ducting: Ideally 150mm diameter circular or 204 x 60mm rectangular ducting should be used. Rigid ducting is recommended, with flexible ducting kept to a minimum (maximum 300mm per leg) and pulled taut. All ducting between the MVHR unit and the atmosphere must be insulated to prevent condensation.
Condensate Drain: The condensate must be discharged under a water level in a U-trap drainpipe or an alternative airlock drain method. The connection is suitable for 21.5mm Ø overflow pipe, and solvent cement should be used for the joint. If the pipe is in an unheated space, it should be insulated to prevent freezing.
Unit Weight:
- ECO3: 24Kg
- ECO5: 25Kg
Spigots: 4 x 150mm diameter.
Safety Features:
- Fitted with surge protection. If RCD protection is used, a G or S type RCD is recommended.
- All-pole disconnection from the mains with a minimum contact separation of 3mm must be incorporated into the fixed wiring.
- Ducting must be securely fixed to prevent access to live parts.
- Precautions must be taken to avoid back-flow of gases from fuel-burning appliances.

Usage Features:

Wall Mounting: The unit is designed for wall mounting, specifically on a solid wall. For non-solid walls (e.g., stud partitions), a minimum 25mm thick MDF panel solidly fixed behind the plasterboard is required.
Loft Mounting (Optional): Can be positioned on a tank stand using an anti-vibration tray assembly (MRXBOX-AV(3/5), purchased separately) or fixed to a 25mm minimum thickness MDF panel vertically across roof trusses using angled brackets (also from MRXBOX-AV(3/5)).
Commissioning: Requires a qualified electrician. Airflow rates must be set according to design specifications or building regulations using a calibrated moving vane anemometer and hood. Adjustment valves should be locked in place post-commissioning.
Integral Automatic HX Bypass: Monitors intake and extract temperatures. If temperatures fall within set parameters, the bypass damper opens automatically to maintain an indoor comfort temperature.
Summer / Winter Switch: When set to "Summer," the automatic summer bypass is fully operational. In "Winter" position, the HX bypass is disabled for continuous heat recovery.
Speed 3 Operation (SW Units Only): Non-operational if intake temperature is greater than extract temperature.
Frost Protection: If intake air temperature drops below -5°C (standard), the supply fan reduces to minimum speed. The fan returns to commissioned speed once the temperature rises. This feature activates after ten days of continuous run time.
Humidity Adjustment (AB units only): An internal humidity sensor in the extract airflow boosts the unit to the commissioned boost speed when humidity exceeds the set point. The set point is adjustable on the front panel.
Status Indication: LEDs on the front cover indicate the unit's status, including Speed 1, 2, 3, Supply Fan Fault, Extract Fan Fault, Frost Protection, Filter Change, and HX Bypass (AB units only). Note that the display does not indicate when a higher speed setting is triggered by an external source (e.g., ES-PIR2).

Maintenance Features:

Filters: Filters must be inspected every 6 months and replaced every 12 months (or sooner if required). A flashing LED indicates a filter change is required, repeating every 12 months and turning off automatically after 5 days. Filter covers are removed by gripping two circular tabs and pulling them away. Filters are extracted by pulling a black removal loop.
General Maintenance: Ensure all covers are fitted before switching on the mains supply. The unit must remain switched on at all times to maintain ventilation and prevent long-term damage.
Warranty: The warranty covers parts and labor for the first year, with subsequent periods covering replacement parts only. It is void if the equipment is modified without authorization, incorrectly applied, misused, disassembled, or not installed, commissioned, and maintained according to the manual and good practice. Only genuine Nuaire parts and filters should be used.
End-of-Life and Recycling: Nuaire products are designed with recyclable components. Fans, motors, controls, electrical components, sheet metal, aluminum, and other metallic items can be segregated into WEEE recycling streams. EPP, plastic ducting, nylon parts, heat exchangers, and packaging can be segregated into mixed plastic recycling. Cardboard-framed filters and other paper components can be processed in energy from waste centers. Remaining items can be processed according to the zero waste hierarchy. Before dismantling, the product must be made safe from electrical/water/refrigerant supplies by a qualified person.