Full Text Searchable PDF User Manual
May 2010
Clyde Alkon 90
Floor standing condensing boilers
Natural Gas
90 kW
LP Gas
90 kW
Engineering Data Sheet 814/1
Contents Page
General information
2 & 3
Dimensions and Data
4
Installation requirements 5 & 6
Boiler wiring diagram
7
Hydraulic systems
8 to 12
Fully modulating burner and efficiency of up to 109.1% ncv
Modulating integral pump
Modular arrangement of floor standing boilers that simply bolt together
Cascade of up to 8 boilers (2 x 4) without additional frames or manifold
Aluminium/silicon/magnesium heat exchanger resists corrosion
Counter flow heat exchange maximises heat transfer & thermal efficiency
For internal and external installations
General information
Key to Figs 1 & 2
1
Non-return valve
2
Isolating valve
3
Modulating pump
4
3-way drain cock
5
Flow temperature sensor
6
Return temperature sensor
7
Low water pressure switch
8
Limit thermostat
9
Air vent
10
Heat exchanger
11 Combustion air fan and venturi
12
Condensate level sensor
13
Exhaust gas outlet (100 mm diameter)
14
Gas valve
15
Gas isolating valve
16
Low gas pressure switch
17
Condensate trap and drain
18
Ignition electrode
19
Ionisation electrode
20
Drain cock
Fig 1 Diagram of operating principles
Fig 2 Component identification for Alkon 90 boiler
Operating principles
The Alkon 90 is a floor standing condensing boiler with a counter flow heat exchanger with heat exchange pins that
ensure a constant rate of heat transfer through the aluminium body. It has a fully-modulating, down-firing pre-mix gas
burner (refer Figs 1 and 2). When operating in condensing mode with a flow of 50
°
C and a return of 30
°
C, it will give
efficiencies of up to 109.1% (ncv). The combustion air fan and venturi (11) accurately control the volumes of gas and air
and mix them in a sealed chamber prior to ignition. This ensures that there is optimum combustion at any point in the
modulation range of the boiler. A small flame is held on the entire surface of the plaque burner.
An integral boiler circulation pump (3) ensures an even and constant flow through the heat exchanger - refer page 8.
This pump modulates to match flow rate to heat output and increases the overall operating efficiency of the Alkon 90
boiler.
System circulating pumps should be hydraulically separated from the boiler(s) by a low velocity header.
EDS814/1 page2
R
F
Gas
1
2
3
4
14
6
8
9
11
12
13
10
16
5
7
15
16
17
9
18
8
19
10
12
16
17
20
3
DN 80
flow
1
6
4
7
5
9
14
11
13
General information
Handling
Offloading, dry storing and placing of equipment in the
boiler room is the responsibility of the installer.
Equipment must be dry stored and protected from frost.
Cartons must not be crushed or otherwise damaged.
Commissioning
Clyde undertake commissioning of boilers. Commissioning
charges do not include servicing during the guarantee
period, although this may be carried out under service
contract or to specific order. Boilers should be
commissioned in line with CIBSE Commissioning Code B.
Servicing
The importance of regular maintenance cannot be over-
emphasised if maximum efficiency is to be maintained.
Customers are strongly advised to place the equipment
under service contract immediately commissioning is
complete.
Application
Alkon 90 boilers are manufactured and tested in accordance with the Gas Appliances Directive 90/396/EEC, the Boiler
Efficiency Directive 92/42/EEC, the Low Voltage Directive 2006/95/EC, the Electromagnetic Compatibility Directive
2004/108/EC, EN 483, EN 625, and EN 677 and CE marked accordingly. They are suitable for use in LTHW heating
systems with a maximum operating pressure of 8.0 bar and a maximum working temperature of 90°C (see Technical
data).
Alkon 90 boilers are suitable for use with Group H second family gases (eg natural gas, G20), and Group P third family
gases (eg propane, G31). and Butane/Propane mix (G30).
The boiler is suitable for use in pressurised (sealed) or open vented heating systems with a minimum static head of 0.5
bar. It is not suitable for use as a direct water heater. Where potable water is required, a matching calorifier or plate heat
exchanger must be provided in the system.
Statutory requirements
The installation and commissioning of the boiler must be carried out by a qualified engineer in accordance with the
instructions provided.
Gas supplies and gas burners must be installed, serviced and commissioned by a qualified person, eg. a Gas Safe
registered engineer.
Guarantee
Subject to correct handling, installation and operation, all
equipment is guaranteed for twelve months from the date
of despatch. Boiler heat exchangers are guaranteed for a
period of two years from the date of manufacture.
The guarantee is not valid if the boiler is not installed in
accordance with these instructions (please refer to page
5), becomes blocked with debris and/or carbonate
deposits from the system water and/or there is no
documented evidence of commissioning by Clyde or their
appointed engineer.
Boiler Log book
A boiler log book that provides a permanent record of
commissioning and servicing data and measurements is
supplied with every boiler. It is recommended that the
owner ensures that this log book is kept safe and brought
up to date on every occasion that routine or emergency
work is carried out on the boiler.
Emitter sizing (radiators)
The boiler will operate in condensing mode whenever the
return water is below 50°C and will reach its full potential if
the flow water temperature is also below 50°C. However,
the latter condition will mainly occur when the boiler is
heating an underfloor heating scheme or transiently when
recharging a DHW storage tank from cold. By careful
design of a traditional heating system with radiators, and
with weather compensating control in operation, the return
water temperature can be held below 50°C for most of the
heating season, only rising above this figure when outdoor
temperatures are below zero.
For optimum performance, calculate heat losses on the
basis of a 20°C internal temperature and a -8°C outdoor air
temperature. With no added factors, size the radiators on
the basis of published EN 442 data ( T50) and size the
system pump for a 20°C temperature drop. In most cases
this will ensure that the boiler begins to operate in
condensing mode when the outdoor air temperature rises
above 1°C and becomes fully condensing when the
temperature is above 5°C. For heating schemes in
buildings where the occupants have special needs,
different environmental conditions may apply and further
advice must be sought.
N
o
n
-c
o
n
d
e
n
s
in
g
0
10
15
20
5
-5
-8
Outdoor air temperature °C
20
30
40
50
60
70
80
C
o
n
d
e
n
s
in
g
°C
B
o
ile
r
°C
Re
turn
w
ate
r te
m
pe
ra
ture
°C
Flo
w
w
ate
r te
m
pe
ra
tu
re
°C
EDS814/1 page3
Dimensions and technical data
EDS814/1 page4
93
Plan
AA
Dim ensions
Bo ile r m o d e l / o u tp u t
kW
9 0
Bo ile r flo w co n n e ctio n
H O
D N 8 0
Bo ile r re tu rn co n n e ctio n
H I
D N 8 0
C o n d e n s a te o u tle t
C o
m m
3 2
Ga s In le t
GI
D N 5 0
Flu e co n n e ctio n
AA
m m
1 0 0
Technical data
Flow 50°C / Return 30°C
H e a t o u tp u t (n cv)
Ma x
kW
9 3 .6
H e a t o u tp u t (n cv)
Min
kW
2 4
H e a t in p u t (n cv)
Ma x
kW
9 0
Efficie n cy (n cv)
1 0 0
%
1 0 4
Efficie n cy (n cv)
3 0
%
1 0 9 .1
Flow 80°C / Return 60°C
H e a t o u tp u t (n cv)
Ma x
kW
8 7 .5
H e a t o u tp u t (n cv)
Min
kW
2 1 .1
H e a t in p u t (n cv)
Ma x
kW
9 0
Efficie n cy (n cv)
1 0 0
%
9 7 .2 6
Efficie n cy (n cv)
3 0
%
9 6 .0 3
Flu e g a s te m p e ra tu re ris e a t fu ll lo a d
°C
3 8 .5
Flu e g a s m a s s flo w
kg /s
0 .0 3 9
C O
2
in flu e g a s (1 )
m in /m a x
%
8 .8 / 9 .6
C O in flu e g a s (0 % o f O2 )
m in /m a x m g /kWh
2 1 .5 / 1 0 4 .4
C n o d e n s a te vo lu m e a t m a x ra te
kg /h
1 4 .5 4
N a tu ra l g a s co n s u m p tio n (g ro s s cv) (2 )
m ³/h
8 .3 6
N 0 x Em is s io n s
m g /kWh
3 5 .6 2
Bo ile r s e a s o n a l e fficie n cy (3 )
%
9 7 .4 1
D ry w e ig h t
kg
1 3 5
Wa te r vo lu m e
l
1 0
Ma xim u m a llo w a b le te m p e ra tu re
°C
90
Ma xim u m h yd ra u lic w o rkin g p re s s u re
b a r
8
C E R e g is tra tio n n u m b e r
1 3 1 2 BR 4 9 2 6
Ele ctrica l p ro te ctio n
X5 D
Ma x e le ctrica l p o w e r co n s u m p tio n
W
3 0 3
N o te s : (1 ) Me a s u re d a t th e flu e g a s a d a p to r (2 ) Ba s e d o n GC V 3 8 .7 6 MJ/m ³
(3 ) C a lcu la te d fro m th e n o n -d o m e s tic h e a tin g a n d co o lin g co m p lia n ce g u id e fo r co n fo rm a n ce w ith AD L 2 A a n d
AD L 2 B 2 0 0 6 u s in g th e fo rm u la
seasonal = 0.81
30%
+ 0.19
100%
W ater flow rates and hydraulic resistances
Wa te r flo w ra te a t 2 0 °C te m p . ris e
l/s
1 .1 2
H yd ra u lic re s is ta n ce a t 2 0 °C te m p . ris e
kPa
2 2
Front
Left elevation
513
129 251 430
607
119
1300
149
315
448
HO
GI
Co
HI
GI
Co
HI
Right elevation
Heat output (ncv)
Installation requirements
Regulations governing installation
Alkon boilers should be installed in accordance with all
prevailing regulations and codes of practice, including the
Building Regulations, Health and Safety Regulations PM5,
Water Bylaws and the current Gas Safety (Installation and
Use) Regulations. Detailed relevant guidance will also be
found in;
BS 6644 :2005
Installation of appliances exceeding 70
kW net input
BS 5449
Forced circulation hot water central
heating systems for domestic premises
CIBSE AM14: 2010 Non-domestic hot water heating
systems
CIBSE Guides B and C and Commissioning Code B
Institution of Gas Engineers Utilization Procedures 1, 1A,
2, 4, 7 and 10.
Water treatment
Alkon 90 boilers have an aluminium/silicon/magnesium
alloy heat exchanger and care must be exercised to
ensure that the system water and any water treatment is
compatible.
Whenever a new boiler is connected to an existing
system, the pipework must be thoroughly cleaned and
flushed. This is to remove debris, rust particles, carbonate
deposits and any existing water treatment that might be
incompatible with the heat exchanger. New systems must
also be thoroughly flushed to remove debris and flux
deposits. Clyde recommend that a permanent means of
filtration be fitted into the return pipework, such as a
sludge trap, hydrocyclone or full flow duplex filters. The
boiler guarantee will be invalid if waterways are blocked
by debris or carbonate deposits.
The pH value of the system water should be measured to
ensure that it is between 6.5 and 8. Temporary hardness
(calcium carbonate and magnesium carbonate) can be
removed by boiling and its effects limited by preventing
ingress of fresh, untreated water. Permanent hardness
must not exceed 15
o
FR (150 mg/litre calcium carbonate).
The boiler guarantee will be invalidated by the use of
incorrect or incompatible water treatment. Specialist
advice should be obtained, eg from;
Fernox
Tel. 01483 793200
For full information on cleaning, flushing and protecting
hot water systems, refer to BSRIA Application Guide AG
1/2001.
Deaeration
It is a condition of warranty that there is effective air
separation and removal from the system. The air
separator should be fitted at the hottest part of the system.
Boiler condensate
Alkon 90 boilers have a 32 mm flexible condensate drain
that is compatible with standard plastic waste pipe. Do
not use other materials, as they will corrode. The pipe
size must not be reduced and there must be a continuous
fall to drain. As a further precaution against freezing,
condensate pipes should be run internally whenever
possible and lagged when run externally.
Pressurisation of systems
Alkon 90 boilers should be installed as part of a
pressurised (sealed) or open vented system with a
minimum pressure of 0.5 bar. The maximum allowable
pressure for the boilers is 8 bar. They are not to be used
with a gravity circulation system.
Boiler location
Alkon 90 boilers can be installed external to a building if
the optional top weather cover is fitted. The boiler must
be mounted on a sound, smooth and level plinth of non-
combustible material, capable of supporting its weight.
The boiler location must be frost-free and adequately
ventilated (see below). Contamination of the combustion
air by inflammable vapours, high dust levels or
halogenated hydrocarbons will constitute a safety hazard
and will damage the boiler.
The following minimum clearances around the boiler
should be observed;
Front
500 mm
Sides
500 mm
Air supply and ventilation
Adequate air for combustion and ventilation is essential to
the safe operation of a boiler. The air for combustion and
ventilation requirements of either BS 6644:2005 or
IGEM/UP/10 must be met. Table 1 shows the
requirements of BS 6644:2005 for boilers with a Type B
flue. This standard requires natural ventilation at both
high and low levels to the outside air, and is based on the
net input of the boilers.
BS 6644:2005 calls for additional ventilation if a boiler is
used for more than 50% of the time during the summer or
if the ambient temperature of the plant room ceiling
exceeds 40°C.
Ventilation direct to
outside air
Total kW input (net)
Low level
4 cm² per kW of total rated net
input
High level
2 cm² per kW of total rated net
input
Table 1 Ventilation for multiple boiler installations in a boiler
room complying with BS 6644:2005
EDS814/1 page5
Installation requirements
Heat exchanger hydraulic resistance
The Alkon 90 boiler has a high resistance heat exchanger. The boilers should be hydraulically separated from the
heating distribution system by either a low velocity header or a plate heat exchanger. With this arrangement, the boiler
pump can be located in the return (where water temperature is lowest) regardless of the location of the system
distribution pumps.
The boiler is supplied with an integral modulating pump that will ensure flow through the heat exchanger and low velocity
header. The advantage offered by a modulating pump over a constant volume circulator is that the T between flow and
return is maximised at all times by the control of mass flow, thus increasing heat exchanger efficiency.
Low velocity headers
Low velocity headers are used to separate hydraulically the boilers from the rest of the system. In addition to helping
maintain a minimum flow through the boiler, they create a low velocity region for system dirt to be deposited and
separation of air from the system water. Used in conjunction with a system filter (refer page 5), they are invaluable when
connecting a new boiler to an existing system.
Low velocity headers should always be vertical and sized for a maximum water velocity of 0.5 m/s. Alkon 90 low velocity
headers are designed to ensure a water velocity of 0.2 m/s or less and for
T10 / 20, so will be suitable for most
systems. Fig 3 shows dimensions for the low velocity header supplied by Clyde, and Table 3 shows dimensions for a
T10 / 20 system.
If the heating distribution system has been designed for <
T20 and a low velocity header has not been installed, the
boiler(s) will not provide heat into the system at their rated heat output.
D
R
½
TO
FILTER
Primary
Circuit
Heating
Distribution
Circuit
BF
BR
HF
HR
R
½
a
b
c
Fig 3 Design for a low velocity header
Number of
boilers in
cascade
D mm
T 10 / 20
Boiler Flow /
Boiler Return
T 10 / 20
Heating Flow /
Heating Return
T 10 / 20
a mm
b mm
c mm
1
DN 125
DN 65 (PN 16)
DN 65 (PN 16)
500
1000
1740
2
DN 125
DN 65 (PN 16)
DN 65 (PN 16)
500
1000
1740
3
DN 200
DN 100 (PN 16)
DN 100 (PN 16)
500
1000
1740
4
DN 200
DN 100 (PN 16)
DN 100 (PN 16)
500
1000
1740
Table 3 Low velocity header dimensions for T 10 / 20 system
EDS814/1 page6
Boiler wiring diagram
EDS814/1 page7
Key to Fig 4
1
Ignition electrode assembly
2
Ionisation electrode
3
Minimum water pressure switch
4
Modulating pump
5
Flow temperature sensor
6
Return temperature sensor
7
DHW temperature sensor (optional)
8
Limit thermostat
9
Flue gas temperature limit thermostat (optional)
10
Gas valve
11
Modulating fan speed control
Fig 4 Schematic wiring diagram
4
3
6
5
7
8
9
2
10
1
11
12
Hydraulic system design and control
Mains connection
Each Alkon 90 boiler requires a permanent mains supply of 230V 50Hz, protected by a 3 Amp fuse. The electrical
supply to the boiler must be installed in accordance with current IEE (BS 7671) Regulations. A separate supply and
isolating switch is required for each boiler, with at least 3 mm separation for both the phase and neutral poles.
Individual boiler operation
Alkon 90 boilers can operate independently of external controls, controlled by their internal flow and return thermostats.
To control boiler operation with a basic room thermostat, programmable room thermostat or time clock, remove the link
between terminals 1 and 2 on the boiler Y1 terminal board and connect to these - see fig 4.
Cascade control, weather compensation and DHW control
The addition of an E8 heating controller, connected to terminals 3 and 4 of the Y1 terminal board, will provide the
following functions;
Cascade control of up to 8 boilers
DHW generation via a calorifier with loading pump, giving DHW priority
Temperature control of one or two heating circuits. The options are one directly controlled index circuit with a mixer
for a secondary circuit, or direct control of the DHW circuit as the index, with two mixers for the two heating circuits
Weather compensation
Integration of a solar thermal system
The E8 controller can be built into a plant room control panel, mounted on the wall, or supplied with an optional wall
mounting box that also serves as a boiler controls wiring centre. An E8 controller is supplied as part of the cascade kit
for 2, 3 and 4 boilers, and as an optional extra for single-boiler configurations if DHW control, temperature control of
more than one heating zone or weather compensation is required.
Outside air sensor, DHW temperature sensor and heating circuit sensors are supplied with the E8 controller. A DHW
complete wiring kit is also available. Refer to the Alkon 90 installation manual for full details and schematics.
Building and Energy Management Systems
A single E8 controller will be required if one or more boilers are to be controlled by a 0 - 10V signal from a BMS or EMS.
If the overall control is by a Modbus Network, the E8 controller should be replaced with a single Boiler Communications
Module (BCM) as the controlling interface. Refer to Alkon 90 installation manual for full details and schematics.
Key to figs 5 to 8
Items supplied as part of standard boiler frame and
pipework kits
1
Alkon 90 master boiler with side panels and
flanges
2
Alkon 90 slave boiler
7
Low velocity header connection pipework
8
Y-filter section
9
Low velocity header
10
E8 controller (not shown) is standard for 2, 3 and
4 boiler cascades, and optional for single boiler
installations (see above)
Items supplied as optional extras to standard boiler
frame and pipework kits
3
Safety device pipework manifold
4
Safety device housing
5
Safety device kit comprising limit temperature
thermostat, maximum pressure switch,
manometer, thermometer, common gas and water
safety valves and boiler expansion vessel
6
Top cover for exterior use
11
BCM (Boiler Communications Module - not
shown)
12
CGCPU Pressurisation unit (not shown)
13
DHW control wiring kit (not shown)
EDS814/1 page8
Hydraulic system design and control
EDS814/1 page9
Notes;
(1) Overall length of the standard frame and pipework kit, which does not include items 3, 4 and 5.
(2) This is the overall length including items 3, 4 and 5. These items are a safety device kit including housing, manifold,
controls and boiler expansion vessel. These are optional items only and must be specifically ordered if required.
Fig 5 1-boiler frame and pipework
3
4
5
6
7
8
9
18
32
(1
)
23
13
(2
)
Hydraulic system design and control
EDS814/1 page10
Notes;
(1) Overall length of the standard frame and pipework kit, which does not include items 3, 4 and 5.
(2) This is the overall length including items 3, 4 and 5. These items are a safety device kit including housing, manifold,
controls and boiler expansion vessel. These are optional items only and must be specifically ordered if required.
Fig 6 2-boiler frame and pipework
23
14
(1
)
27
95
(2
)
Hydraulic system design and control
EDS814/1 page11
Notes;
(1) Overall length of the standard frame and pipework kit, which does not include items 3, 4 and 5.
(2) This is the overall length including items 3, 4 and 5. These items are a safety device kit including housing, manifold,
controls and boiler expansion vessel. These are optional items only and must be specifically ordered if required.
Fig 7 3-boiler frame and pipework
293
4 (1
)
341
5 (2
)
Hydraulic system design and control
Notes;
(1) Overall length of the standard frame and pipework kit, which does not include items 3, 4 and 5.
(2) This is the overall length including items 3, 4 and 5. These items are a safety device kit including housing, manifold,
controls and boiler expansion vessel. These are optional items only and must be specifically ordered if required.
Fig 8 4-boiler frame and pipework
34
17
(1
)
38
98
(2
)
Units 13 - 14 Charlwoods Rd
East Grinstead
West Sussex RH19 2HU
e :
info@clyde4heat.co.uk
w :
clyde4heat.co.uk
Clyde Energy Solutions Ltd
This publication is issued subject to alteration or withdrawal without notice. The illustrations and specifications are not binding in
detail. All offers and sales are subject to the Company's current terms and conditions of sale, a copy of which is available on request.