Dimensions; Heating System Design - Saunier Duval ISOFAST F 28 E Installation And Operating Instructions Manual

DIMENSIONS

The ISOFAST is delivered in three separate packages:
- the boiler itself
- the fixing jig
- the flue system
Weight: 51,2 kg
X
= 470 (96)
552 (120)
Diagram 5

HEATING SYSTEM DESIGN

The ISOFAST is compatible with any type of ins-
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tallation.
Heating surfaces may consist of radiators, con-
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vectors or fan assisted convectors.
The ISOFAST can be piped directly to an under-
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floor heating system without the need for a mixing
bottle. The maximum central heating flow tem-
perature can be set to 53°C.on the boiler printed
circuit board during commissioning.
Pipe sectional areas shall be determined in ac-
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cordance with normal practices, using the output/
pressure curve (diagram 4). The distribution system
shall be calculated in accordance with the out-
put requirements of the actual system, not the
maximum output of the boiler. However, provision
shall be made to ensure sufficient flow so that the
temperature difference between the flow and re-
turn pipes be less than or equal to 20°C. The mini-
mum flow is 400 l/h.
The piping system shall be routed so as to avoid
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any air pockets and facilitate permanent venting
of the installation. Bleed fittings must be provided
at every high point of the system and on all radia-
tors.
The total volume of water permitted for the heat-
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ing system depends, amongst other things, on the
static head in the cold condition. The expansion
vessel on the boiler is pressurised at 0,5 bar (corre-
sponding to a static head of 5 m w.g.) and allows
a maximum system volume of 160 litres for an aver-
age temperature of 75°C and a maximum service
pressure of 3 bar. This pressure setting can be modi-
fied at commissioning stage if the static head dif-
fers. An additional expansion vessel can be fitted
to the system if required, see diagram 8.
Provision shall be made for a drain valve at the
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lowest point of the system.
Where thermostatic radiator valves are fitted, not
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all radiators must be fitted with this type of valve,
and in particular, where the room thermostat is in-
stalled.
In the case of an existing installation, it is ESSEN-
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TIAL that the system is thoroughly flushed prior to
installing the new boiler.
Filling the system
The ISOFAST is supplied with a built-in filliing de-
vice, see diagram 7.
7