Unit must not be switched off during normal operation, the
product is designed to run continuously.
1.0 Introduction
MRXBOX95B-LOFT is designed to provide mechanical supply
and extract ventilation with heat recovery and incorporates
summer bypass.
The unit is fitted with two independent fans. Each fan has full
speed control for background and boost ventilation rates as
well as a run-on timer facility. To recover heat from the extract
air the heat exchanger block is utilised. This heat exchanger
can recover up to 95% of the normally wasted heat.
The bypass damper opens when a 230V switch signal is
applied to the unit (via a manual switch). This opens the
damper via a wax actuator. When the switch signal is de-
activated the unit returns to its original state (air through
the heat exchanger).
Outside air supplied through the bypass is still being filtered,
so the air quality is optimal, irrespective of the bypass setting
(Open or closed).
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.
The fan must be installed indoors, away from direct sources of
frost, heat, water spray or moisture generation.
The unit is designed for mounting on the roof joists in the loft
space using four “L shape” metal brackets and four A.V.
mounts supplied with the unit. Please note that various
positions for the brackets are available to suit different joist
centres.
Connect the four ‘L’ shape fixing brackets to the unit with the
M4 screws (provided) they can be attached to the long, or
short sides of the unit depending on requirements. Each pair of
brackets should be mounted at different heights so the fall is
towards the drip tray end of the unit. (see figures 2a, 2b and
2c for fixing details). Lower the unit with the “L” shape fixing
brackets attached onto the joists. Mark through the brackets
and drill four clearance holes into the top surface of joists.
Locate anti-vibration mounts (supplied) above and below each
bracket fixing point hole and, using 4 suitable screws (not
provided) and washers, fix the unit to the joists (see fig 2b).
Do not overtighten the fixings. The distance from the top
washer on the A.V. mount to the joist when installed must
not be less than 30mm.
Nuaire Limited
Western Industrial Estate Caerphilly United Kingdom CF83 1NA
T: 029 2088 5911 F: 029 2088 7033 E: info@nuaire.co.uk W: www.nuaire.co.uk
1
Leaflet Number 671453 January 2011
MRXBOX95B-LOFT
Mechanical Ventilation Unit with Heat Recovery
& Summer Bypass for Loft Mounting
Installation and Maintenance
The EMC Directive
2004/108/EC
The Low Voltage
directive
2006/95/EC
Spigot 1.
(non control
side).
125mm dia.
Spigot 3.
125mm dia.
Spigot 4.
125mm dia.
Spigot 2.
125mm dia.
Three alternative
150mm dia knockout
spigots on rear of unit.
One alternative
150mm dia knockout
spigot on side of unit.
Figure 1. Airflow through unit.
Spigot Location and Ducting references:
Spigot 1.
Extract air from kitchen/bathroom.
Spigot 2.
Intake air from outside.
Spigot 3.
Outside air to house.
Spigot 4.
Extract air to outside.
Figure 2a. Mounting MRXBOX95B-LOFT onto roof joists using
the ‘L’ shaped fixing brackets and AV mounts with four suitable
screws on the long side of the unit.
Controls
21.5mm dia.
condensate pipe.
Two fixing
brackets
should be
attached on
the non-control
end of the unit
via
the two
upper hole
positions.
(see figure 2c).
The two fixing brackets on the control end of the MRXBOX95 unit should be
attached via
the two lower hole positions.
(see figure 2c).
