Vent-Axia HR4 Quick guide

HR4
Semi-Remote Wall Mounted Heat Recovery Unit
With Spigot Connections & Integral Fans
Installation and
Servicing Instructions
Please leave these instructions with the user

2

3
1.0Introduction 4
2.0Site Requirements 5
3.0Installation 6
4.0Electrical 8
5.0Maintenance & Accessories 9
6.0Notes 10
Section Page
Contents

1.0 Introduction
4
1.1 Description
1. The Vent-Axia HR4 unit is self contained, with
integral extract and supply fans to provide
balanced ventilation and heat recovery via
supply diffusers and extraction grilles.
The unit is designed for installation in external
walls and should be fitted to provide a 3° slope
to outside to provide condensate drainage.
2. Spigots are designed to take standard
300mm diameter flexible ducting. Foam collar
adaptors are available to convert these spigots
to 315mm diameter compatibility.
3. The unit is fully speed controllable with the
facility to reverse the supply air fan and provide
‘double extraction’ for periods when heat loss is
desirable.
4. ON/OFF speed selection and fan reversal
can be automatically controlled by simple
sensors - see controller data sheet VCON33.
5. At 40 pa external static pressure the HR4
unit will deliver approximately 500m3/hr supply
and extraction, or 750m3/hr extract only.
1.2 Technical Data
Electrical
Supply Fan - 60 Watts
Extract Fan - 150 Watts
Wiring - 0.75mm2, 4 core and earth
(N.B. Wiring must be approved to BASEC
or HAR)
Fixing
Hole Opening - 610mm x 380mm
Unit Weight - 17kg
150
100
50
0 200 400 600 800 1000
3
Volume m /hr
Static Pressure (Pa)
Performance Curve
A - Mean heat recovery performance
B - Double extract performance
C - Supply
D - Extract
CD
B
A
300
200
100
2000 400
3
Volume m /hr
600 800 1000
0
Pressure Drop (Pa)
Pressure Drop
Fig. 1
Fig. 2
Fig. 3

2.1 Information
1. The unit must be sited and connected in
accordance with current I.E.E. Wiring
Regulations (UK), and local building regulations.
Outside the UK, the units must be installed in
accordance with the appropriate standards
applicable to your country.
2. The unit is suitable for use at a maximum
ambient temperature of 45°C.
3. The HR4 unit should be placed as high as
possible, in an exterior wall to a minimum
distance of 125mm (5”) from the ceiling.
4. The incoming air supply should not be
directed at a wall or solid surface and areas
adjacent to doors should be avoided if possible.
5. Care should be taken to avoid structural
elements such as joists or beams.
6. Site away from direct sources of heat in
excess of 40°C, and direct water spray.
7. Precautions must be taken to avoid the back
flow of gases into the room from the open flue
of Gas or other Open Flue appliances.
8. The installer must ensure that the air intake is
located at a minimum distance of 500mm away
from any flue outlet.
9. If the unit is installed within a room containing
a fuel burning appliance, the installer must
ensure that the air replacement is adequate for
both the unit and the fuel burning appliance.
10. Wiring must be via a fused switched spur
with a 3mm contact separation in each pole.
11. Before deciding on the final position of the
unit, check that there are no buried cables,
pipes or obstructions on the outside wall.
2.0 Site Requirements
5
3°
Fig. 4
Fig. 5
Fig. 7
Fig. 6
600mm
Supply
External Grille
Extract
SupplyExtract
Heat Exchanger
Cover Bolts
370mm
600mm
570mm
480mm
340mm
750mm
380mm
11”Cavity Wall
3°Angle for
condensate drainage

3.0 Installation
6
3.1 Initial Preparation
1. Working from the inside, mark out the
position of the hole to be cut. This should be
610mm (24”) x 380mm (15”) (Fig. 8).
2. Mark the centre of the cut-out by drawing
diagonal lines from the four corners.
3. Drill horizontally through the wall at the
marked centre point, using an appropriate long
reach drill.
4. Estimating the wall thickness, move to the
outside and mark the position of the hole to be
cut in the outer wall, using the centre hole as a
guide. Again, this should be 610mm (24”) x
380mm (15”) (Fig. 8). However, to allow for
condensate drainage, the hole must be marked
between 12mm-30mm (0.5”-1.25”) LOWER
than the inner hole (Fig. 9). This will produce a
nominal 3°slope towards the outside
(assumption of installation into wall thickness
dimension between 230mm - 610mm (9”-24”)).
5. Using the lines as a basis, carefully cut the
holes in the inner and outer walls to form a
suitable aperture to receive the unit.
NOTE: Bricks will cut more easily and
accurately if a series of holes are drilled
close together along the marked lines.
6. Choose a suitable site for the controller or
switch box, and run a suitable length of cable (5
core, 0.75mm2) to the unit for wiring through the
left hand side.
3°
Fig. 9
Fig. 8
12 to 30mm
Inside Outside
610mm (24”)
380mm
(15”)

3.0 Installation
7
3.2 Installing the Appliance
1. Carefully line up the unit into the wall
aperture, ensuring that the wire is fed into the
unit through the grommet as shown.
2. Position the unit in the wall aperture,
ensuring that there is a 3°slope to the outside.
CAUTION: Care should be taken not to
distort either inner or outer cases when
fixing and making good.
3. Secure into position using appropriate plugs
and screws, and make good around the casing.
4. Connect the wire into the controller box within
the unit, ensuring that the cable restraint
prevents the cable from becoming strained,
twisted or forced.
5. Ensure that the product is wired in
accordance with the details attached.
WARNING: Ensure that the unit is
properly earthed.
6. Connect up the opposite end of the wire into
respective controller, ensuring that the cable is
routed between the unit and the controller box
appropriately, and that the wire is not strained,
twisted or forced.
7. Make good the cable routing.
8. Connect up the mains supply via an
appropriate fused switched spur, ensuring that
a 5A fuse is correctly fitted.
3°
Fig. 10
Lay-in Eggrate
Grille
External
Wall
3°Slope
Suspended Ceiling
Typical Installation
Lay-in 4 Way
Diffuser

4.0 Electrical
8
5
4
3
2
1
E
Link
HR4 Terminal
Block
Direct to mains -
Full speed only -
Heat recovery mode
Fused Isolation
Switch
Neutral
Live
Earth
9
10
11
2
0
1
12
13
14
NOTE: The sensor arrangement
can be used with single
or dual unit control
Humidity Sensor HS6 Wiring Control of Boost Speed Switching
Link
VCON33
Terminals
HS6
Terminals
5
4
3
2
1
E
HR4 Terminal
Block
Direct to mains -
Full speed only -
Heat recovery mode and
switching to extract only
Fused Isolation
Switch
Live
Neutral
Earth
Switch for
Heat Recovery mode
or Extract Only
9
10
11
12
13
14
NOTE: Remove link between terminals 10 & 11
Automatic 'Boost Speed' Wiring
N/O
N/C
Link
Auto
Common
Switched
VCON33
Terminals
Changeover
Sensor
1
2
3
4
5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
L
N
VCON 33S
Terminal Block
HR4 Unit
Terminal Block
Single HR4 unit wiring
VCON 33S speed controller
E
E
Capacitor 10uF
Capacitor 7uF
5A Fuse
Link
Link
Mains
Supply
230V 50Hz
1.0-1.5mm Cable
2
5
4
3
2
1
E
HR4 Terminal
Block
Variable speed
controller VCON5 -
Heat Recovery mode and
switching to Extract Only L
N
2
1
E
Fused Isolation
Switch
VCON5
Terminal
Live
Neutral
Earth
Switch for
Heat Recovery mode
or Extract Only
9
10
11
12
13
14
NOTE: Remove link between terminals 13 & 14
Automatic 'Extract Only' Wiring
N/O
N/C
Link
Auto Boost
Common
Switched
VCON33
Terminals
Changeover
Sensor
Optional External Sensor Wiring
Sensors must be ‘make and break’(changeover) type,
mains voltage minimum 2.5A inductive load.
Automatic Extract Only Control
By removing the link between terminals 13 and 14, a
changeover sensor can be connected to terminals 12, 13
and 14 to provide automatic supply fan reversal for
extraction only mode of the HRV unit. Example; a
thermoswitch can be used to provide extract only and
therefore heat loss at a preset temperature level.
Automatic Boost Speed Switching
By removing the link between terminals 10 and 11, a
changeover sensor can be connected to terminals 9, 10
and 11 to provide automatic switching to boost speeds as
required.
Example; A humidistat can be used to switch the unit to
boost when high humidity levels are reached, as would be
experienced from activity in a swimming pool. The unit
would automatically return to normal speed 1 or 2 once the
humidity levels have been reduced.
For dual unit control using VCON 33S see Controller Data Sheet
4.1 Wiring Options

5.0 Maintenance & Accessories
9
5.1 Cleaning the Unit
1. The heat exchanger will require occasional
cleaning to remove build up of deposits.
2. The cassette is easily extracted by
unscrewing the 4 x M6 cover bolts (Fig. 11).
3. Debris can be removed and cleaned by using
a vacuum cleaner, or by washing in luke warm
soapy water.
4. In heavily polluted and smoky environments,
it is recommended that the heat exchanger unit
is examined for cleaning puposes every 3
months.
5. Spare cassettes are available to enable
immediate changeover of soiled units, which
can be cleaned for later use.
5.2 Accessories
1. Speed Controller VCON 33S
Speed controller for surface mounting, 3 speed
and fan reversal.
2. Speed Controller VCON 5
ON/OFF variable speed controller mounted on
a standard one gang switch plate and supplied
with a plastic surface mounting back box.
Fig. 11
Cover Bolts
Cover Bolts
Heat Exchanger

6.0 Notes
10

11

A Division of Vent-Axia Limited.
Fleming Way, Crawley, West Sussex RH10 9YX
Technical support:- 01293 526062 Fax:- 01293 539209
Internet Site at:- www.vent-axia.com
370695B- 0904