Mitsubishi Electric PQHY-P250YHM-A, Справочник данных

Страница: 45 / 78

- 36 -
(4) Piping system
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 MULTI 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.
Œ
When well water is used for heat source water.
Œ
When piped to outdoor or a place where freezing may be caused.
Œ
When vapor condensation may be generated on piping due to an increase in dry bulb temperature caused by the entry of
fresh outdoor air.
System example of water circuit
Heat
source
unit
Indoor unit
Backflow prevention valve
Pump
Strainer
3-way valve
3-way valve
Cooling tower
Heating tank
Flexible joint
Refrigerant piping
Valve
Joint
Drain
Y-shape strainer
Heat
source
unit
Indoor unit
Heat
source
unit
Indoor unit
Heat
source
unit
Indoor unit