Compression raises the r ef rigerant temperat ur e ab ove that of the water flowi ng through the
condenser tubes. Whe n th e warm (typically 98 to 10 2 F [ 37 t o 40 C]) refrigerant vapo r comes
into contact with the cond ens e r tubes, the relativel y coo l c ond ensing water (typica lly 85 t o 95 F
[29 to 35 C]) removes some of t he he at and the vapor condense s into a liquid.
The liquid refrigera nt passes through an orific e int o the FLASC chamber. Bec au se the
coolest condenser wa te r is flowing through the FL ASC, it is at a lower pressu r e and part of the
entering liquid ref r ige rant will flash to vapo r , t her e by cooling the remaining liquid. The vapor is
then recondensed by the conde nser water flowin g through the FLASC chamber.
The subcooled liquid re fri gerant drains into a hig h-side valve chamber wh ic h m et ers the
refrigerant liquid int o a flash economizer chamb er. Pressure in this ch am be r is intermediate
between condenser and cooler pressures. At thi s lower pressure, some of t he li quid refrigerant
flashes to gas, further c oo ling the remaining liq uid. The flash gas, havin g absorbed heat, is
returned directly to the compressor second stage. Here it is mixed with discharge gas that is
already compressed by the first-stage impeller. Since the flash gas has to pa ss through only
half the compression c y c le, to reach condenser press u re, there is a savings in po wer.
The cooled liquid ref r ige rant in the economizer is me te red through the low-sid e valve
chamber into the cooler. Because pressure in the c oo ler is lower than econo m iz er pr e ssure,
some of the liquid flashes an d cools the remainder t o ev ap orator (cooler) tempe rature. The
cycle is now complete.