Dimplex ST0133 User Manual
SOLAR
Technical Manual
Complete guide to Dimplex Solar
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1 Contents
1 CONTENTS 2
2 BEFORE YOU START 4
G
ENERAL 4
3 SOLAR THERMAL 4
3.1
INTRODUCTION 4
3.2
SOLAR RADIATION 4
3.1.1 Available solar radiation 4
3.1.2 Orientation 6
3.3
SOLAR THERMAL SYSTEM 8
3.3.1 Components of a solar thermal system 8
3.3.2 Function of a solar thermal system 10
4 DIMPLEX SOLAR PRODUCTS 11
4.1
DIMPLEX SOLAR COLLECTOR SOLC220 11
4.1.1 General description 11
4.1.2 Hydraulic collector connection 13
4.1.3 Roof fixing kits 17
4.1.4 Space requirement 22
4.1.4 Technical data 24
4.2
DIMPLEX SOLAR CONTROL UNIT SOLCU1/2/3 24
4.2.1 General description 24
4.2.2 Temperature sensors 25
4.2.3 Technical data 26
4.3
DIMPLEX SOLAR PUMP UNIT SOLPU1/2 26
4.3.1 General description 26
4.3.2 Pump connection 30
4.3.3 Technical data 31
4.4
DIMPLEX SOLAR EXPANSION VESSELS SOLEV 32
4.4.1 General description 32
4.4.2 Expansion vessel sizing 32
4.4.3 Technical data 35
4.5
DIMPLEX EXPANSION VESSEL FIXING KIT SOLVK1 35
4.5.1 General description 35
4.5.2 Technical data 36
4.6
DIMPLEX HEAT TRANSFER MEDIUM SOLHT20 36
4.6.1 General description 36
4.6.2 Technical data 37
4.7
DIMPLEX SOLAR CYLINDERS SCX 37
4.7.1 General description 37
4.7.2 Wiring integration Dimplex solar cylinders SCx 39
4.7.3 Hydraulic integration Dimplex solar cylinders SCx 42
4.7.4 Technical data 43
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4.8 DIMPLEX SOLAR ACCESSORIES 44
4.8.1 General description 44
4.8.2 Corrugated flexible pipe SOLFH10/15 45
4.8.3 Feed through tiles SOLFTT and SOLFTM 46
5 SYSTEM SIZING 47
5.1
REQUIRED INFORMATION 47
5.2
SIZING GUIDE 47
6 PIPE WORK 49
6.1
TYPE OF PIPE WORK 49
6.2
PIPE WORK SIZING 49
6.3
PIPE WORK PRESSURE DROP 50
6.4
PIPE WORK LIQUID CONTENT 50
6.5
PIPE WORK FIXATION 51
6.6
PIPE WORK INSULATION 51
7 COMMISSIONING 52
8 OPERATION 53
8.1
CONTROL UNIT 53
8.2
PUMP UNIT 55
9 MAINTENANCE 55
10 PRODUCT AND KIT LISTINGS 58
10.1
DIMPLEX SOLAR KITS 58
10.2
DIMPLEX SOLAR COMPONENTS 58
11 DIMPLEX LITERATURE STRUCTURE 60
12 APPENDIX 61
12.1
ON SITE QUESTIONNAIRE 61
12.2
ON SITE INSPECTION 62
12.3
DIMPLEX SOLAR SYSTEM DIRECT – OVERALL VIEW 65
DIMPLEX SOLAR SYSTEM INDIRECT – OVERALL VIEW 66
12.4
12.5
EXAMPLE DIMPLEX SOLAR SIMULATION REPORT 67
13 NOTES AND SKETCHES 72
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2 Before you start
General
Thank you for your interest in Dimplex Solar products. We trust this manual will give
you all the answers to the questions that you might have regarding the products. Although every care was taken to ensure the content of this manual is correct we do not
accept any liability for claims resulting directly or indirectly from the application of the
information contained in this manual.
This manual is written specifically for the Dimples Solar product range. Any information
contained therein must not be applied generally to any other solar products.
Should you require any further assistance please do not hesitate to contact us.
3 Solar thermal
3.1 Introduction
The sun supplies every day a multiple of the required world wide daily energy demand
to the earth. The energy of the sun is available in various forms such as:
- direct, diffuse and reflected solar radiation
- wind
- waves
- the ground and in other forms.
Solar thermal systems convert the energy incident from the sun on an absorber surface
into sensible heat in form of hot water. Depending on the temperature required and
achieved, this hot water can be used for a whole range of applications as summarised in
Figure 1.
Figure 1 – Approximate temperature ranges of some solar thermal applications
3.2 Solar radiation
3.1.1 Available solar radiation
Solar thermal systems can only utilise the energy from the sun in form of solar radiation.
The solar radiation can be incident on the solar panels in various forms which are shown
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in Figure 2, namely direct, reflected and diffuse radiation. The various types of radiation
can occur in isolation but in most cases the radiation incident on a solar thermal collector is a combination thereof.
<200 W/m²
<600 W/m²
<1000 W/m²
<1200 W/m²
Figure 2 – Forms of incident solar radiation
direct + reflected
strong
diffuse
diffuse
direct
The solar radiation available outside the earth’s atmosphere, the so called extraterrestrial radiation, has a density of 1367 W/m². Depending on:
- the location of the solar system
- the time of day and year
- the “obstacles” in the atmosphere such as cloud cover and pollution
- and the inclination of the solar system in relation to the sun
this value varies strongly. A map of the United Kingdom and Ireland is shown in Figure
3, indicating average annual solar energy gains on the horizontal surface.
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Figure 3 – UK and Ireland irradiation map (horizontal surface)
3.1.2 Orientation
The solar irradiance shown in Figure 3 is an average value incident on the horizontal
surface. As mentioned above, depending on the orientation and inclination of the solar
collector the incident radiation onto the collector surface can vary although it might be
in the same location.
The terminology used to describe the exact location and orientation of a solar collector
is described in Figure 4. The terms indicate:
- longitude: geographic coordinate for East/West measurement
- latitude: geographic coordinate North or South of the equator
- slope: angle between the horizontal and the collector plane
- azimuth: angle between South and the perpendicular to the collector pane (West
+90°, South =0°, East -90°)
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S U N
W
L
a
t
i
t
u
Zenith
d
e
Slope
N
e
d
u
t
i
g
n
o
L
Azimuth
S
Figure 4 – Terminology to describe location and orientation of solar thermal panel
E
Figure 5 – Effect of orientation on incident radiation levels
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Although the location of the solar thermal system can be described using the longitude
and latitude of the installation, in practise the locality is being used to determine the
location of the system.
The effect of the orientation on the incident solar radiation levels can be seen from Figure 5.
3.3 Solar thermal system
3.3.1 Components of a solar thermal system
Although solar thermal systems cover a whole range of applications, see Figure 1, the
basic components used are in principle the same. A solar thermal system consists of:
- solar collector
- heat transfer medium
- pipe work
- pump and safety equipment
- heat exchanger
- storage facility
- control unit
- user
Applying the above to a domestic hot water system, the individual components are
identified in Figure 6.
control
storage cylinder
with build in
heat exchanger
transfer medium
pump and safety
equipment
solar
collector
pipe
work
heat
Figure 6 – Solar system components overall view
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Each component in the solar thermal system fulfils a specific function which is described
below:
Solar thermal collector
The solar thermal collector receives the solar radiation, converts it into thermal energy
and passes it on to the heat transfer fluid.
Heat transfer fluid
The heat transfer fluid circulates through the solar collector, the pipe work and the heat
exchanger. It transfers the energy gained by the collector into the storage device. The
heat transfer fluid has additional properties such as frost protection and anti-corrosion
inhibitors to ensure a long and reliable operation of the solar thermal system.
Pipe work
The pipe work connects the various components of the solar thermal system to allow
the heat transfer medium to transport the energy from the collector to the storage device. The pipe work must be insulated and both, the pipe work and the insulation must
be of appropriate material for solar thermal applications.
Pump and safety equipment
The pump and safety equipment are combined in the pump unit. Beside the actual circulation pump the pump unit contains a flow meter, flush and fill point, air separator,
non return valves, manual thermometers, isolating valves, pressure relief valve, pressure gauge and the connection point for the expansion vessel.
Heat exchanger
The heat exchanger allows a hydraulic separation of systems but allows the transfer of
energy between the two systems, i.e. the solar circuit and the wholesome water. In a
domestic solar thermal hot water system the heat exchanger is usually in form of a coil
immersed in the wholesome water inside the hot water cylinder.
To ensure the solar thermal system works at its optimum efficiency, the heat exchanger
has to be sufficiently sized and positioned correctly within the hot water cylinder.
Storage facility
The storage facility is most likely to be a domestic hot water cylinder or a buffer vessel.
As the solar thermal system will not always be able to supply all of the required energy,
it is important that an auxiliary heating system is available to boost the system as and
when required.
The storage facility should be of such design that all energy sources can work independent of each other without compromising each others efficiencies, giving solar thermal the priority to allow for maximum energy gain.
Control unit
The control unit has the primary function of switching the circulation pump on and off
ensuring that the maximum amount of energy is being transferred from the solar thermal collector into the storage facility.
The control unit is usually also the user interface with the system and has therefore a
display and additional functions to ease the operation, maintenance and control of the
system.
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User
The user varies from installation to installation but has a big influence on the operation
of the solar thermal system. However, the system has all components to ensure the
provision of the comfort levels that the user expects.
3.3.2 Function of a solar thermal system
Bearing in mind the function of the individual components, the function of a solar thermal system is in principle very simple. Based on two measured temperatures, one in
the hottest (T1) and one in the coldest (T2) part of the system, the control unit
switches the pump either on or off depending on the temperature difference between T1
and T2 and the temperature reached in the storage device. The location of the temperature sensors is indicated in Figure 7.
T1
Figure 7 – Location of temperature sensors in solar thermal system
If T1 is greater than T2 plus an additional temperature differential (called ΔT ‘delta T’),
the circulation pump is being switched on by the control unit to transfer the energy
from the collector into the storage device. As soon as this on condition is not given, the
pump is being switched off.
The solar control unit also ensures that the water in the cylinder is not being heated
above a set temperature which can be freely chosen and is measured by the temperature sensor T2.
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A more detailed description of the function of the individual components follows in
Chapter 4, Dimplex solar products.
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4 Dimplex solar products
The following section details the product features and relevant technical data of the
components of the Dimplex solar offering. Where applicable a general description of the
component’s function is given.
4.1 Dimplex solar collector SOLC220
4.1.1 General description
The Dimplex solar collector SOLC220 is a solar thermal flat plate collector. A cross sectional drawing of the Dimplex SOLC220 is given in Figure 8 detailing the individual collector components.
(A) Collector cover (glass)
(B) Absorber plate (aluminium)
(C) Powder coated frame (aluminium)
(D) Manifold pipe (copper)
(E) Collector insulation (mineral wool)
Figure 8 – Flat plate collector components
Due to its construction, a flat plate collector is subject to conduction, convection and
radiation heat losses. The sum of these heat losses and the design and production quality are summarised in the thermal collector efficiency which is empirically determined
through independent third party testing and expressed in Equation 1. The heat loss
modes of a flat plate collector are shown in Figure 9.
(F) Meander pipe (copper)
(G) High selective absorber coating
(H) Back plate (aluminium)
(I) Secure cover fixation
(J) Continuous mounting channel
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2 3 4
7
5
2
()
−
ηη
tt
⋅−=
a
G
−
tt
amam
⋅−
a
210
[1]
G
Where:
a
a
η [-] thermal collector efficiency
η
[-] optical collector efficiency/zero loss coefficient
0
[W/m²/K] linear heat loss coefficient
1
[W/m²/K²] squared heat loss coefficient
2
G [W/m²] global incident radiation
t
t
[°C] collector middle temperature
m
[°C] collector ambient temperature
a
6
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9
1
8
Figure 9 – SOLC220 heat loss modes
The collector heat loss front (7) and collector heat loss back (8) are dependant on the
operating conditions of the solar thermal collector, i.e. primarily on the temperature
difference between the collector module and the ambient air and wind speed. Applying
equation 1 to the Dimplex SOLC220 collector the graph shown in Figure 10 can be derived.
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Figure 10 – Thermal efficiency curve Dimplex SOLC220 flat plate collector
Figure 10 shows that the higher the temperature difference between the collector module and the ambient is, the lower is the efficiency of the product. Due to the required
operating conditions of various applications (see Figure 1) the collector has to operate
at varying efficiencies.
In general central heating support applications are not recommended with solar thermal
except if the whole system is especially designed for the application offering all the required features such as collector orientation, storage, heating operating temperatures,
heating demand and others.
Beside the thermal efficiency of the solar collector various other parameters are of importance for the correct application thereof. All of these parameters are determined in
accordance with EN12975 and some of them are detailed in Figure 25, Technical details
Dimplex SOLC220.
4.1.2 Hydraulic collector connection
The hydraulic integration of the solar thermal collector in the overall system is critical to
ensure the most efficient and reliable operation of the installation. When integrating the
collector, the following aspects have to be considered:
- installation space availability
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- collector design
- collector pressure drop
- flow rate
- required system output
Figure 11 shows the Dimplex SOLC220 collector with the pipe work attached to the absorber plate indicated.
C
Figure 11 – Absorber pipe work Dimplex SOLC220 collector
From Figure 11 it can be seen that the collector has 4 connections which can be used to
connect the flow and return pipes of the installation and to connect the collectors between each other. The 4 connections offer the following features:
- one collector for small or large installations
- left hand or right hand side connection of single collector installations
- up to 10 collectors directly connected together
- collectors connected in parallel to each other, thus low overall pressure drop of array
- same collector for vertical or horizontal installations
The sensor pockets to connect the collector sensor T1 from the control unit are always
on the side with the connections marked (A) and (C). It is important to ensure that all
of the pipe work within the collector is being utilised:
- for single collector installations, the flow and return pipes must be installed on connections (B) and (D).
- for multiple collector installations the sensor pockets must always face outwards.
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The flow and return of the collector are connected using a 800mm long insulated corrugated stainless steel flexible hose (9.1). The interconnections consist of short flexible
bellows (10.1). The remaining connections are to be blanked off using the blanking
pieces (9.2). The connections components are depicted in Figure 12 using the same
references as in the installation manuals.
Figure 12 – Connection components Dimplex SOLC220 collector
An overall view of the application of the individual connection components is given in
Figure 13 (two collectors, flow left hand side, return right hand side). Note: the sensor
pockets on both collectors face outwards.
Figure 13 – Typical connection of Dimplex SOLC220 collector
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An overall view of possible collector connections is given in Figure 14 detailing also the
pressure drop at nominal low-flow and high-flow flow rates.
No. of collectors
Flow rate
[l/min]
Pres. drop
[mbar]
1
2
3
4
5
6
7
8
1
2
2
4
3
6
4
8
5
10
6
12
7
14
8
16
150
325
150
330
150
330
160
340
160
340
170
350
185
385
195
400
10
9
9
18
10
20
200
420
210
500
Figure 14 – Collector connection options, flow rates and pressure drop
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Although only the vertical collector orientation is shown, the same principles can be
applied to the horizontal collector installation. The same applies for the positioning of
the flow and return, it can be changed from left to right hand side as long as the sensor
(indicated by dot) is moved accordingly.
Note: Up to 5 collectors can also be connected single sided with the orientation of the
individual collectors as shown in Figure 14 and the sensor placed in the sensor
pocket on the collector flow.
4.1.3 Roof fixing kits
The Dimplex solar collectors SOLC220 can be installed in most situations on or near a
building. An overall view of the installation options is shown in Figure 15.
A
B
E
C
H
F
G
Figure 15 – Dimplex Solar collector installation options
D
Dimplex offers a wide range of roof fixing kits for the installation of the SOLC220 solar
collector. The available roof fixing kits are summarised in Figure 16.
Flashing kits are available as accessory for the integrated roof kits to cover the sides, bottom
and the gap between the collectors.
Figure 16 – Dimplex solar roof fixing kits overall view
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On roof kits
The on roof kits come as basic and extension kit. The basic kit has to be ordered for
each first collector of a collector field, the extension kit for each additional collector in
the installation.
Corrugated
tile
Plain tile
Slate
Figure 17 – On roof mounting options
Sheet metal
As detailed in Figure 16 the on roof kits suit various types of roof coverings. The different mounting methods for the various tiles are shown in Figure 17 differing only in the
design of the bracket/fixation of the collector support rail to the roof structure.
In roof kits
The in roof kits are only available for vertical collector installation and vary for tile roof
coverings and slate covering only. Additional flashing kits are available to complement
the integrated roof kits, covering the pipe work on the side of the collector, the fixing
brackets at the bottom and the gap between the collectors.
The in roof kits and flashing kits are not sold as basic and extension kits but come as
complete kits for 2, 4 and 6m² installations. Should a larger collector field be installed,
further extension kits are available.
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Integrated roof kit
without flashings fitted
Figure 18 – Dimplex SOLC220 integrated roof kit without and with flashing kit fitted
Integrated roof kit
with flashings fitted
Free standing kits
The free standing kit is designed for the vertical installation of the solar collector on
even ground with a slope of 45° to 60°. For lower sloping angles shorted support struts
can be ordered, allowing the collector to slope between 30° and 40°.
As shown in Figure 24, the free standing mounting kit is usually fixed at 4 individual
points. Alternatively a U – section rail is available as accessory aiding on uneven ground
or for suspended installation.
When more than one row of solar collectors is being installed it is important to minimise
the impact of shading of one row to the other. Equation 2 can be used to calculate the
optimum row spacing to avoid shading at solar noon on the least favourable day of the
year, i.e. 21
st
December.
180sin1870
_
mm
=
cp
sin
α
αβ
+−°⋅
()()
s
s
[2]
Where: p_c [mm] pitch between collector rows
β [°] sloping angle of solar collector
α
[°] solar altitude angle
s
The solar altitude angle can be calculated applying Equation 3 or approximating it from
Figure 19.
s
φφα
)45.23sinsin45.23cos(cos90 °⋅+°⋅−°=
[3]
Where:
α
[°] solar altitude angle
s
φ [°] latitude of installation
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Figure 19 – Free standing kit row distance calculation details
In addition to the row distance the fixation of the free standing kit to the mounting surface has to be considered carefully. Due to the shape of the flat plate collector considerable wind forces can act on the free standing kit installation.
Ideally the free standing kit is bolted to a fixed structure. However, this is not always
practicable, especially when the roof surface must not be penetrated for water tightness reasons.
Equation 4 is to be used to calculated the required mass to securely locate the free
standing kit. The required parameters can be found in Figure 20.
Note: the stated parameters are only valid for the wind speeds stated in Figure 20. It is
the responsibility of the installer/mechanical engineer to validate these figures for the
individual installation. Dimplex does not accept any liability for damage to material,
buildings or persons resulting from free standing installations not being sufficiently supported.
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r
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mnmnm ⋅−⋅= [4]
colcolsptspttot
Where: m
n
m
n
m
[kg] minimum mass required
tot
[-] number of supports in installation
spt
[kg] mass for each support (see Figure 20)
spt
[-] number of collectors in installation
col
[kg] mass of collector (SOLC220 = 34.5 kg)
col
Figure 20 – Free standing kit support weight calculation details
In some cases it might be required to prepare the load baring structure in advance to
accept the fittings of the Dimplex solar free standing kit. Figure 21 details the support
feet (4x for each collector) and the free standing bottom bar (2x for each collector).
Support feet Free standing bottom ba
Figure 21 – Fixation details Dimplex solar free standing kit
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4.1.4 Space requirement
Depending on the mounting method the foot print required by the solar collector installation varies. The dimension for the on roof and free standing mounting kits do not include the space required to fit the connection pipes as these vary depending on the pipe
feed through chosen. The dimensions provided for the integrated roof kits include the
pipe work as the pipe feed through is part of the integrated roof kit.
Figure 22 – Space requirement Dimplex SOLC220 on roof installation
Figure 23 – Space requirement Dimplex SOLC200 in roof installation
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