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7. SYSTEM DESIGN GUIDE
DATA G10
HEAT SOURCE UNITS
WY
4) Piping system
System example of water circuit
The following items should be kept in your mind in
planning / designing water circuits.
a)
All units should be constituted in a single circuit in
principle.
b) When plural numbers of the water heat source CITY
MUL
TI unit are installed, the rated circulating water flow
rate should be kept by making the piping resistance to
each unit almost same value. As an example, the reverse
return system as shown below may be employed.
c) Depending on the structure of a building, the water circuit
may be prefabricated by making the layout uniform.
d) When a closed type piping circuit is constructed, install an
expansion tank usable commonly for a make-up water
tank to absorb the expansion/contraction of water caused
by temperature fluctuation.
e) If the operating temperature range of circulation water
stays within the temperature near the normal temperature
(summer : 29.4°C[85°F], winter : 21.1°C[70°F]), thermal
insulation or anti-sweating work is not required for the
piping inside buildings.
In case of the conditions below, however, thermal
insulation is required.
• When well water is used for heat source water.
• When piped to outdoor or a place where freezing may
be caused.
• When vapor condensation may be generated on piping
due to an increase in dry bulb temperature caused by
the entry of fresh outdoor air.
Heat
source
unit
Indoor unit
Backflow prevention valve
Pump
Strainer
3-way valve
3-way valve
Cooling tower
Heating tank
Flexible joint
Refrigerant piping
Va
lve
Joint
Drain
Y-shape strainer
Heat
source
unit
Indoor unit
Heat
source
unit
Indoor unit
Heat
source
unit
Indoor unit
