Defrosting Operation - Daikin ALTHERMA HT Service Manual

ESIE09-08B

3.2 Defrosting Operation

The defrost operation is performed to solve frost on the outdoor unit heat exchanger when
heating mode is active to recover the heating capacity.
[Conditions to start]
The defrost operation is started referring following conditions.
 Outdoor heat exchanger heat transfer co-efficient
 Temperature of heat-exchange (Tb) < T
 Timer (25 min. the minimum)
*T
[Fan defrosting]
 When compressor stops, 80 sec. at low RPM
 At start up compressor, 30 sec. at 950 RPM (step 9)
 Then goes back to normal RPM
Function
In addition, outdoor heat-exchanger co-efficient is derived from Tc, Te, and the compressor
load.
can vary but is at least -10°C
def
*
def
Special Control
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