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FTC4 Installation Manual
20
Expansion Vessel
Each Mitsubishi Electric pre-plumbed cylinder is supplied with a suitably sized expansion vessel (white) for the
associated volume of potable water.
In the case of a sealed primary circuit an additional expansion vessel will be required, this needs to be sized to
accommodate the expansion within the entire heat emitter circuit and associated pipework. The installer will need
to make this selection based upon the below sizing equation.
Model
HU150FTC4ST HU180FTC4ST HU(S)210FTC4ST
HU(S)250FTC4ST HU(S)300FTC4ST
Expansion Vessel Size
12 Litres
19 Litres
19 Litres
19 Litres
24 Litres
Where:
V : Necessary expansion vessel volume
ε
: Water expansion co-efficient
G : Total volume of water in the system
P
1
: Expansion vessel setting pressure
P
2
: Max pressure during operation
Graph above is for the following values:
ε
: at 70ºC = 0.0229
P
1
: 0.1MPa
P
2
: 0.3MPa
* 30% safety margin is added
Expansion Vessel Sizing
Summary of Contents for Ecodan HUS210FTC4ST
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Page 8: ...5 Pipework Configuration 8 FTC4 Installation Manual ...
Page 20: ...20 FTC4 Installation Manual 14 Ecodan Only System Schematic ...
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