Solar System; Expansion Vessel Sizing Chart - gledhill BoilerMate A-Class OV SOL Series Design, Installation & Servicing Instructions

DESIGN

Solar System

5 amp
junction box
Expansion
vessel
Pressure
gauge
Appliance
control board
Solar
control board
OV SOL
SZ - Thermal store
solar zone sensor
Solar coil

Expansion Vessel Sizing Chart

System Height
(metres)
System Volume
Vessel size/pre-charge pressure/initial fill pressure
(litres)/Maximum
Collector Area (m 2 )
<10/5 18/1.3/1.6
20/7.5 25/1.3/1.6
30/12.5 35/1.3/1.6
50/15 40/1.3/1.6
Note: System height refers to the difference in height from the top of the collector
to the expansion vessel.
SC - Collector flow temperature sensor
Solar panel (collector)
Return
Flow
(to panel)
(from panel)
60
40 80
20 100
0 120
Solar pump
SR - return
temperature/
flow sensor
BMA
2.5 5.0
(litres/bar/bar)
18/1.5/1.8
25/1.5/1.8
35/1.5/1.8
50/1.5/1.8
A schematic layout of a solar system
incorporating a BoilerMate A-Class OV SOL
appliance is shown above.
As can be seen, the BoilerMate A-Class OV SOL
appliance includes almost all the equipment
normally provided in a solar pumping station.
On this basis, the flow and return pipework
from the solar panel(s) (collectors) should be
run directly from the panel to the BoilerMate
A-Class OV SOL.
A 6 bar pressure relief (safety) valve will be
required on the solar return to the solar collector.
PRV
discharge
To allow future maintenance/testing, its location
pipe
shall be accessible. The discharge pipe shall
be of a rigid and non-deformable constitution
Fill and flush valve,
ie. metal. No valves should be fitted in the
check valve and
pipework between the solar collector and the
temperature gauge
pressure relief (safety) valve. The discharge
assembly
from the pressure relief (safety) valve shall
terminate in a position where the discharge of
steam/scalding water will not cause any injuries
or harm to persons or property. A suitably sized,
high temperature receptacle, an internal gulley or
at low level externally, are all normally considered
acceptable termination points. However, a high
level termination from walls or on roofs is not
normally considered acceptable because of the
Extent of the
possible harm to people below.
components
included with
the BMA OV SOL
A suitable solar expansion vessel will also be
required and a 15mm connection with pressure
gauge is provided on the top of the appliance.
The vessel shall be sized and the initial filling
pressure established in accordance with an
Figure 1.13
approved method such as set out in Appendix
D of the Solar Heating, Design and Installation
Guide produced by the Domestic Building
Services Panel of the Chartered Institute of
Building Services Engineers.
10.0
However, the chart opposite provides an
indication of the likely vessel size and fill
pressures required when using a flat plate
collectors and a 6 bar safety valve (allowing 1.0
bar over pressure).
18/2.0/2.3
The collector flow temperature sensor (SC) is
35/2.0/2.3
wired into the BoilerMate OV SOL complete
40/2.0/2.3
with 2.5 metres of cable (2 x 0.75mm
insulated). However, dependant on the location
50/2.0/2.3
of the solar panel(s) this may need extending
by the installer on site (up to a maximum of
50 metres). It is recommended that the cable
is jointed in a 5amp junction box fitted in the
roof space adjacent to the panel(s). The sensor
(6mm diameter) will need to be fitted in the
solar panel or flow pipe from the solar panel as
near to the panel as possible.
The solar panel(s), expansion vessel, pressure
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