Space-Ray CBU09 User guide

FormForm
Overhead Radiant Tube Heaters
INSTALLATION, SERVICING AND OPERATING
INSTRUCTIONS
Gas Fired Products (UK) Ltd.
Chapel Lane, Claydon, Ipswich
Suffolk IP6 0JL, England
Tel: [phone] Fax: [phone]
E-mail: [email protected]
www.spaceray.co.uk
CBU09 CBU12
CBU15 SRU25
ERU25 SRU30
SRU35 SRU40
SRU45
SRL09 SRL12
SRL15 SRL25
SRL30 SRL35
SRL40 SRL45

Form 483S
Rev Jan 09
Page 1 of 53
INSTALLATION, SERVICING AND OPERATING INSTRUCTIONS
Before installation, check that the local distribution conditions, nature of gas and pressure, and adjustment of appliance
are compatible.
INDEX
Section Title Page
1. Safety 2
2. Installer Responsibility 2
3. Technical Data 3 - 6
4. Un-Packing 7 - 10
4.1 CBU 09/12/15 SRU25 ERU25 7
4.2 SRU 30/35 SRU 40/45 8
4.3 SRL 09/12/15 SRL 25 9
4.4 SRL 30/35 SRL 40/45 10
5. Installation 11 - 20
5.1 Suspension 11
5.2 Gas Supply 13 - 14
5.3 Electrical Supply 14 - 15
5.4 Ventilation 16 - 20
6. Assembly 21 - 44
6.1 CBU 09/12/15 21 - 23
6.2 SRU25/ERU25 24 - 26
6.3 SRU30/SRU35 27 - 29
6.4 SRU40/SRU45 30 - 32
6.5 SRL09/12/15 33 - 35
6.6 SRL 25 36 - 38
6.7 SRL 30/35 39 - 41
6.8 SRL 40/45 42 - 44
7. Commissioning 45 - 47
7.1 Ignition 45
7.2 Shut Down 45
7.3 Checking Gas Pressure 45 - 47
7.4 Flame Supervision 47
7.5 Air Proving Switch 47
8. Servicing 47 - 49
8.1 Fan 47
8.2 Control Box 48
8.3 Reflector 49
8.4 Flue Pipes 49
8.5 Re-assembly and Commissioning 49
8.6 Auxiliary Controls 49
9. Replacing Components 49 - 51
9.1 Fan 49
9.2 Electrodes 49 - 50
9.3 Ignition Control 50
9.4 Air Proving Switch 50
9.5 Burner Assembly 50
9.6 Injector 50
9.7 Pre-injector 50
9.8 Twin Solenoid Control Valve 51
9.9 Neon Indicators 51
9.10 Replacement Parts List 51
10. Conversion Instructions 51 - 52
10.1 Conversion from Natural Gas to LPG 51 - 52
10.2 Conversion from LPG to Natural Gas 52
11. Operating Instructions 52

Form 483S
Rev Jan 09
Page 2 of 53
INSTALLATION, SERVICING & OPERATING INSTRUCTIONS
1. SAFETY
This heater is a self-contained overhead radiant tube heater designed for non-domestic use. Safety information
required during installation and operation of this heater is provided in this manual and the labels on the product.
The installation, service and maintenance of this heater must be performed by a contractor qualified in the
installation and service of gas fired heating equipment.
All personnel in contact with the heater must read, and understand, all safety information, instructions and labels
before operation. The following symbols will be used in this manual to indicate important safety information.
Warning instructions must be followed to prevent or avoid hazards which
may cause serious injury, property damage or death.
Caution instructions must be followed to prevent incorrect operation or
installation of the heater which may cause minor injury or property damage
2. INSTALLER RESPONSIBILITY
The installer is responsible for the following:
•The heater and venting, as well as electrical and gas supplies must be installed in accordance with these
installation instructions and any applicable codes and regulations.
•Every heater shall be located with respect to building construction and other equipment so as to permit access
to the heater.
•Each installer must follow the clearances to combustibles materials for the heaters.
•Install the heater so that the supports and hangers are correctly spaced in accordance with these instructions.
The heater must be supported by materials having a working load limit of at least 52kg.
•Supply the owner with a copy of these Installation and Operation Instructions.
•Never use the heater as a support for a ladder or other access equipment. Do not hang anything from the
heater.
•Supply all installation materials necessary that are not included with the heater.

Form 483S
Rev Jan 09
Page 3 of 53
3. TECHNICAL DATA
Table 1
MODEL CBU09/SRL09-N CBU09/SRL09-L
Heat Input 9.0 kW Hs 8.1 kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector Ø2.4mm Ø1.45mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions CBU 09 3.10m x 0.46m SRL 09 5.493m x 0.34m
Weight CBU 09 31kg SRL 09 27kg
Gas Connection R - ½
Flue Size Ø100mm
Table 2
MODEL CBU12/SRL12-N CBU12/SRL12-L
Heat Input 11.4 kW Hs 10.3 kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector No. 36 Ø1.65mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions CBU 12 3.10m x 0.46m SRL 12 5.493m x 0.34m
Weight CBU 12 31kg SRL 12 27 kg
Gas Connection R - ½
Flue Size Ø100mm

Form 483S
Rev Jan 09
Page 4 of 53
Table 3
MODEL CBU15/SRL15-N CBU15/SRL15-L
Heat Input 15. kW Hs 13.5 kW Hi
Appliance Type A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Setting Pressure 12.5mbar None
Injector No. 31 Ø1.9mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions CBU 15 3.10m x 0.465m SRL 15 5.493m x 0.34m
Weight CBU 15 31kg SRL 15 27kg
Gas Connection R - ½
Flue Size Ø100mm
Table 4
MODEL SRU25/SRL25/ERU25-N SRU25/SRL25/ERU25-L
Heat Input 23.0 kW Hs 20.7 kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector Ø3.8mm Ø2.3mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions SRU25/ERU25: 5.385m x 0.465m SRL25: 10.065m x 0.34m
Weight SRU25: 47kg ERU25: 47kg SRL25: 46kg
Gas Connection R - ½
Flue Size Ø100mm

Form 483S
Rev Jan 09
Page 5 of 53
Table 5
MODEL SRU30/SRL30-N SRU30/SRL30-L
Heat Input 29.2 kW Hs 26.3 kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector No. 19 Ø2.6mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions SRU30: 5.51m x 0.715m SRL30: 9.955m x 0.34m
Weight SRU30: 66kg SRL30: 62kg
Gas Connection R - ½
Flue Size Ø100mm
Table 6
MODEL SRU35/SRL35-N SRU35/SRL35-L
Heat Input 34.5 kW Hs 31.1 kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector No. 15 No. 35
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions SRU35: 5.51m x 0.715m SRL35: 9.955m x 0.34m
Weight SRU35: 66kg SRL35: 62kg
Gas Connection R - ½
Flue Size Ø100mm

Form 483S
Rev Jan 09
Page 6 of 53
Table 7
MODEL SRU40/SRL40-N SRU40/SRL40-L
Heat Input 42.2kW Hs 38.0kW Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector ø5.0mm ø3.2mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions SRU40: 6.97m x 0.715m SRL40: 13.00m x 0.34m
Weight SRU40: 81kg SRL40: 79kg
Gas Connection R - ½
Flue Size Ø100mm
Table 8
MODEL SRU45/SRL45-N SRU45/SRL45-L
Heat Input 47.0 Kw Hs 42.3 Kw Hi
Appliance Type (II2H3+) A2, B22, C52
Appliance Category II2H3+
Adjusted for 2H G20 20mbar 3+ G30/G31 29/37mbar
Appliance Type (II2H3P) A2, B22, C12, C32, C52
Appliance Category II2H3P
Adjusted for 2H G20 20mbar 3P G31 37mbar
Setting Pressure 12.5mbar None
Injector ø5.4mm ø3.3mm
Pre-injector None None
Electrical Supply 230V~50Hz 125W
Fuse Externally 3A
Dimensions SRU45: 6.97m x 0.715m SRL45: 13.00m x 0.34m
Weight SRU45: 81kg SRL45: 79kg
Gas Connection R - ½
Flue Size Ø100mm

Form 483S
Rev Jan 09
Page 7 of 53
4. UN-PACKING
4.1 CBU09/12/15
SRU25/ERU25
The appliances are supplied as follows:-
Table 9
MODEL REF CBU09/12/15 SRU/ERU25
Carton (containing the following)
Control Box Assembly
Fan Assembly
U Bend
Hanger Bracket
Torctite Coupling
Fastenings Pack
Radiant Tube (Ø76.2 x 4572)
Radiant Tube (Ø76.2 x 2285)
Reflector Panel (2540 long)
Reflector End Panel (notched)
Reflector End Panel (Plain)
1
2
3
4
5
6
7
8
9
10
1
1
1
1
2
2
1
-
2
1
1
1
1
1
1
1
3
2
1
2
-
2
1
1
CBU09/12/15
Fig 1 SRU/ERU25
Fig 2
9
8
10
7
4
1
2
5
5
1
2
9
8
3
10
4
6

Form 483S
Rev Jan 09
Page 8 of 53
4.2 SRU30/35
SRU40/45
The appliances are supplied as follows:-
Table 10
MODEL REF SRU30/35 SRU40/45
Carton (containing the following)
Control Box Assembly
Fan Assembly
U Bend
Hanger Brackets
Torctite Coupling
Fastenings Pack
Radiant Tube (Ø101.6 x 4572)
Radiant Tube (Ø101.6 x 1524)
Reflector Panel (long)
Reflector Panel (short)
Reflector End Panel (notched)
Reflector End Panel (plain)
1
2
3
4
5
6
7
8
9
10
11
1
1
1
1
3
2
1
2
-
2
-
1
1
1
1
1
1
4
4
1
2
2
2
1
1
1
SRU30/35
Fig 3 SRU40/45
4
6
5
1
3
11
2
10
8
7
4
5
9
6
1
2
8
3
11

Form 483S
Rev Jan 09
Page 9 of 53
4.3 SRL09/12/15
SRL25
The appliances are supplied as follows:-
Table 11
MODEL REF SRL09/12/15 SRL25
Carton (containing the following)
Control Box Assembly
Fan Assembly
Hanger Brackets
Torctite Coupling
Fastenings Pack
Radiant Tube (Ø76.2 x 4572)
Reflector Panel (1511 short)
Reflector Panel (3035 long)
Reflector End Panel
1
2
3
4
5
6
7
8
1
1
1
3
3
1
1
1
1
2
1
1
1
4
4
1
2
-
3
2
SRL09/12/15
Fig 5 SRL25
3
5
1
4
8
6
7
8
7
3
1
4
5

Form 483S
Rev Jan 09
Page 10 of 53
4.4 SRL30/35
SRL40/45
The appliances are supplied as follows:-
Table 12
MODEL REF SRL30/35 SRL40/45
Carton (containing the following)
Control Box Assembly
Fan Assembly
Hanger Brackets
Torctite Coupling
Fastenings Pack
Radiant Tube (Ø101.6 x 4572)
Radiant Tube (Ø101.6 x 3048)
Radiant Tube Assy (turbulator)
Reflector Panel (3035 long)
Reflector End Panel
1
2
3
4
5
6
7
8
9
1
1
1
4
3
1
1
-
1
3
2
1
1
1
5
4
1
1
1
1
4
2
SRL30/35
Fig 7 SRL40/45
Fig 8
3
5
4
1
7
9
2
8
53
2
1
9
8
4
6
7

Form 483S
Rev Jan 09
Page 11 of 53
5. INSTALLATION
Not withstanding their limited scope, the appliance should be installed in accordance with the relevant
provisions of any National Gas Safety (Installation and Use) Regulations. Due account should also be taken of
any obligations arising from any National Heath and Safety at Work Regulations, National and Local Building
Regulations and National Electrical Wiring Regulations. The appliance must be installed, and where necessary,
converted for use on other gases, by a qualified installer.
5.1 Suspension
Burner must be secured to the mounting flange with nuts.
All materials used to suspend the heater must have a minimum working load
of 52 kgs.
Never use the heater to support a ladder or other access equipment.
Failure to do so may result in death serious injury or property damage.
SUSPENSION HAZARD
5.1.1 'U' Tube Heaters should be suspended to provide a slope down to the 'U' bend of 25 mm maximum Linear
Tube Heaters should be suspended to provide a slope up to the fan of between 25 mm and50 mm. The
appliance should be located with respect to building construction and other equipment to permit access to the
appliance for servicing etc.
5.1.2 For suspending the appliance it is recommended that suitable protected welded chain (Ø3mm x 65 links per m)
or Ø8mm min mild steel drop rods and suitable brackets are used. Attach the chains or drop rods to the hanger
brackets where shown (see section 4). Providing at least Ø5mm closed link hooks are used chains may be
attached directly to the hanger brackets.
5.1.3 The appliance may be mounted horizontally or at a recommended angle of 300maximum to the horizontal as
shown below.
IMPORTANT: when 'U' Tube Heaters are angle mounted (fig 9 & 9a) the fan should be assembled to the
higher of the two emitter tubes as shown.
CBU09/12/15 SRU30/35/40/45 SRL09/12/15/25
SRU25 ERU25 SRL30/35/40/45
Horizontal Mounting Horizontal Mounting Horizontal Mounting
Angle Mounting
(recommended to 30°)
Fig. 9a
Angle Mounting
(recommended to 30°)
Fig. 9
Angle Mounting
(recommended to 30°)
Fig. 10
Latch Latch Latch
Latch Latch
Latch
Neon Lights
Neon Lights Neon Lights
Neon Lights Neon Lights Neon Lights
30° 30° 30°

Form 483S
Rev Jan 09
Page 12 of 53
5.1.4 The control box must be supported with a welded chain after overall heater suspension is complete. The is to
prevent control from sagging and burning tube out prematurely. Assemble bracket and turnbuckle to inlet end of
control as shown.
5.1.5 Adjust the turnbuckle until control box is level. Use a levelling device to verify.
Turnbuckle
Bracket
M6 Nut & Washer
Fig. 10a
Adjust turnbuckle
to level control.
Fig. 10b
Level
Welded Chain
Failure to install the burner box suspension
chain vertically will void the manufacturers
warranty.

Form 483S
Rev Jan 09
Page 13 of 53
5.1.6 Minimum clearance from combustibles:-
END END
ABOVE (CEILING) ABOVE (CEILING)
BELOW BELOW
SIDE SIDE FRONT
REAR
Fig. 11
Table 13
MODEL SIDE ABOVE BELOW END FRONT REAR
CBU09-15/SRL09-15 450 450 1220 450 575 305
SRU25/ERU25/SRL25 510mm 450mm 1220mm 510mm 610mm 305mm
SRU30-45/SRL30-45 760mm 610mm 2285mm 610mm 760mm 380mm
5.2 Gas Supply
Radiant tube heaters will expand and contract during operation. Therefore it is essential to provide a flexible
metallic hose, which must conform, to national or Local Regulations, to connect the appliance to the gas supply.
Minimum size to be ½" (12.7mm) bore.
The gas pipe, flexible hose and connections must be self supporting. The gas pipe work must not bear any
of the weight of the heater or any other suspended assembly.
5.2.1 Natural Gas - G20 at 20mbar nominal supply pressure (appliance cat 2H)
Maximum supply pressure (Pmax) 25mbar
Minimum supply pressure (Pmin) 17mbar
Setting pressure 12.5mbar
Gas connection R - ½
Explosive and flammable objects liquids and vapors close to the
heater may result in explosion or fire.
All Combustible materials must be located outside the clearance
dimensions listed.
Failure to do so may result in death serious injury or property
damage.
Tighten flexible gas hose and components securely.
Flexible metal gas hoses must be installed without any twists or
kinks in them. The hose will move during operation of the heater
and it can crack if it is twisted.
Failure to do so may result in death serious injury or property
damage.

Form 483S
Rev Jan 09
Page 14 of 53
5.2.1.1 Installation pipes should be fitted in accordance with National and Local Regulations. Pipes of a smaller size
than the heater connection (R - ½) should not be used and the pipework must be designed to achieve a gas
supply pressure between the maximum and minimum values stated above, measured at the appliance inlet
pressure test point.
A union service cock MUST be fitted as close as practicable upstream of the heater to enable the gas train to
be removed for maintenance or repair.
5.2.1.2 Check that the gas fuel on the burner data plate matches the fuel for the application.
5.2.2 LPG - G30/G31 at 29/37mbar nominal supply pressure (appliance cat. 3+).
Maximum supply pressure (Pmax): G30 - 35mbar
G31 - 45mbar
Minimum supply pressure (Pmin): G30 - 20mbar
G31 - 25mbar
Note:- for appliance cat 3+ the governor is not operational
Gas connections:R - ½
5.2.2.1 The appliance should be connected to a permanent piped supply of LPG with pipes of adequate size to achieve
a gas supply pressure between the maximum and minimum valves stated above, measured at the appliance
inlet pressure test point.
5.2.3 The complete installation MUST be tested for soundness in accordance with National or Local Regulations.
5.3 Electrical Supply
5.3.1 The electrical wiring to this heater must be installed in accordance with the latest or current National
Regulations and any Local Regulations, which apply.
Electrical supply 230V~50Hz 125W
Current rating 0.55
Fuse externally 3A
5.3.2 Twin core and earth PVC covered flexible supply cable (0.5mm2-to National or Local standard specification)
must be used, with connection made as follows:-
THERMOSTAT SWITCHTHERMOSTAT SWITCH
HEATER 1 HEATER 2
GREEN/YELLOW
BLUE
BROWN
7
N
L
7 7
SINGLE HEATER PER THERMOSTAT
Failure to do so may result in death or serious injury.
This appliance must be connected to a properly earthed electrical source.
Disconnect electrical power and gas supply before servicing.
ELECTRIC SHOCK HAZARD

Form 483S
Rev Jan 09
Page 15 of 53
7
L
N
HEATER 1
7
MULTIPLE HEATERS PER THERMOSTAT
SWITCH
BROWN
BLUE
GREEN/YELLOW
HEATER 2
7
SWITCH
THERMOSTAT
Fig. 12
Notes:-The method of connection to the electrical supply must facilitate complete isolation and should
preferably be via a fused double pole isolator having a constant separation of at least 3mm in all poles and
supplying the appliance ONLY.
Alternatively, connection may be made via a fused 3 pin plug and unswitched, shuttered socket, both
complying with the requirements of National or Local Regulations. Neither thermostat nor switch are
supplied as standard equipment.
N.B. In the event of an electrical fault after installation of the appliance, preliminary system checks are
required to be carried out i.e. earth continuity, polarity and resistance to earth.
5.3.3 Internal Wiring Diagram
Fig. 13
N
G/Y
BL
R
BR
G/Y
BL
G/Y
BL
BR
V
R
V
W
N.O.
COM.
N.C.
BL
BR
G/Y
GR
Y
12 346
58 79111210
LLN
WIRING COLOUR CODES
BL = BLUE
BR = BROWN
GR = GREY
G/Y = GREEN & YELLOW
V = VIOLET
R = RED
W = WHITE
Y = YELLOW
AMBER NEON
RED NEON
3.5

Form 483S
Rev Jan 09
Page 16 of 53
5.4 Ventilation
These appliances may be installed with an exhaust flue fitted or without an exhaust flue fitted.
5.4.1 Flueless (Unflued)
The installation room should have a volume of at least 10m³/kw of installed nominal heat input of the radiant
heater.
The ventilation requirements and calculation methods for unflued appliances are set out in the European
Standards EN 13410:2001 and must be applied. The following is guidance to the standard:
Ventilation may be achieved by any of the three following different means:
a) thermal evacuation of the products of combustion/air mixture
b) mechanical evacuation of the products of combustion/air mixture
c) natural air change
5.4.1.1 Ventilation by Thermal Evacuation
Ventilation by thermal evacuation is sufficient if 10m³/h of exhaust air per kW of operating heat input are
ventilated out of the installation room.
The air/products of combustion mixture must be evacuated above the radiant heaters, if possible near the ridge,
by means of exhaust mixture opening(s), (vents).
Where the exhaust mixture opening(s) can be closed, it shall only possible to operate the radiant heaters when
they are open.
The maximum horizontal distance between a radiant heater and a vent opening shall be:
6 (six) times the vent height in the case of wall openings
3 (three) times the vent height in the case of roof openings
5.4.1.2 Ventilation by Mechanical Evacuation
Ventilation by mechanical evacuation is sufficient if 10m³/h of exhaust air per kW of operating heat input are
ventilated out of the installation room.
The air/products of combustion mixture must be evacuated above the radiant heaters using fan(s).
It shall only be possible to operate the radiant heaters whilst the exhaust airflow is proven.
The maximum horizontal distance between a radiant heater and a fan shall be:
6 (six) times the fan mounting height in the case of wall openings
3 (three) times the fan mounting height in the case of roof openings
Total minimum proven ventilation airflow in m³/h will be:
Total installed kW input X 10
Note: Mechanical exhaust air openings must be positioned such that the burner stability of the nearest
appliance is unaffected.
Failure to do so may result in death serious injury property damage or illness
from Carbon Monoxide poisoning.
In buildings with airborne contamination such as poultry houses the heater
must be installed with fresh air for combustion.
Heaters installed unvented must be installed in an area with at
least 10m
3
/ hr per kW heat input of outside air ventilation.
POISONOUS GAS AND SOOT HAZARD

Form 483S
Rev Jan 09
Page 17 of 53
5.4.1.3 Ventilation by Natural Air Change
Gas-fired radiant heaters may be operated without any special exhaust system if the exhaust gases are
discharged to the outside atmosphere by a sufficient natural air change in the installation room.
Furthermore, no provision for thermal or mechanical ventilation is required in the following particular cases:
Buildings with natural air change greater than 1.5 volumes per hour
Buildings with a density of operating heat input not greater than 5W/m³
5.4.1.4 Air Supply
Air supply openings are required to admit air and shall be located below the radiant heaters.
The total area of the unobstructed cross-sections of all the air supply openings shall not be smaller than the
total area of the unobstructed cross-sections of all the exhaust openings.
Slits and gaps of fixed cross-section can also be used as air supply openings.
Where the air supply openings can be closed, it shall only be possible to operate the radiant heaters when they
are open.
5.4.2 Flued
If the appliance is to be flued externally, then flue pipe of diameter stated in table 14, and complying
with National and Local Regulations should be used.
IMPORTANT: When flued horizontally, the flue pipe must be arranged to provide a continuous rise from the appliance
of 25mm per 1m length.
The ventilation requirements for flued appliances is set out in BS 6896:1991 and must be applied.
The following is guidance to the standard:
5.4.2.1 Natural Ventilation
Low level ventilation shall be provided in all cases below the level of the heater(s).
Up to and including 60kW - 4.5cm2/kW
Over 60kW - 270cm2+ 2.25cm2 /kW in excess of 60kW total rated heat input.
Where the air supply openings can be closed, it shall only be possible to operate the radiant heaters when they
are open.
5.4.2.2 Mechanical Ventilation
Ventilation shall be provided in all cases at or below the level of the heaters.
Minimum proven air flow - 2.35m3/h/kW of total rated heat input.
It shall only be possible to operate the radiant heaters whilst the ventilation airflow is proven.
5.4.2.3. The heaters can be installed with different flue and combustion air configurations please review the diagrams
on the following page for the overview of the permitted installations. The permissible maximum lengths
associated with these options are listed in the table below.
Table 14
Flue
Type Max Combustion
Air 100mm Ø
Max Flue
Length
100mm Ø
Max flue length
Concentric
150/100mm Ø
Max length
combined
combustion air
and flue
Reduce length
for 90° bends
100mm Ø
Reduce length
for 90° bends
concentric
A215m N/A N/A 15m -1.7m N/A
B22 13m 15m N/A 28m -1.7m N/A
C12 1 8m + 1m 8m + 1m 1m + 8m + terminal 9m -1.7m -2.5m
C32 18m + 1m 8m + 1m 1m + 8m + terminal 9m -1.7m -2.5m
C52 13m 15m N/A 28m -1.7m N/A

Form 483S
Rev Jan 09
Page 18 of 53
Note1: first length is parallel section second length is concentric section.
A2 - Fresh air horizontal A2 - Fresh air vertical
B22 - Fresh air and flue horizontal B22 - Fresh air and flue vertical
B22 - Flue horizontal B22 - Flue vertical
C52 - Fresh air & Flue horizontal in different pressure
zones
C52 - Fresh air vertical & Flue horizontal in different
pressure zones
C12 - Fresh air & Flue horizontal in concetric ducts
C12 - Fresh air & Flue horizontal in concetric ducts
C32 - Fresh air & Flue vertical in concetric ducts
C52 - Fresh air horizontal & Flue vertical in different
pressure zones
Fig. 14
5.4.2.4. Type A2:
Outside (ducted) combustion air supply. When installed in a dusty or polluted atmosphere, the heater should
be fitted with a ducted supply of clean fresh air. A length of 100mm flexible ducting should be installed between
the Control Box Air Inlet and any rigid ducting and be secured to the Air Inlet with hose clips.
Where outside combustion air is ducted directly to the burner(s) the low level natural ventilation openings shall
be not less than 50%of the areas given in 6.4.2.1 above.
5.2.4.5. Type B22:
When installing external flue single duct systems with ducted combustion air supply the distance between the
flue terminal and fresh air intake shall be no less than 1 m for both vertical and horizontal systems
5.2.4.6. TypeC12:
The following figure shows the typical arrangements for concentric sidewall flues, see table 14 for 90° bend
equivalent lengths. The bends shown in the illustrations connecting the combustion air intake to the concentric
ducts is calculated into the overall length. For example a system with one additional 150/100mm Ø concentric
90° bend can be installed with 1m 100mm flue single pipe and the combustion air single pipe as shown with
5.5m of 150/100mm Ø straight concentric flue. (8m – 2.5m from table 14)
Note: Type C12 is not approved for the CBU15 / SRL15. Type C12 is approved U-Tube models only.