Thermodynamic Defrosting - BWT M.P.I. 100M Notice D'installation Et Conseils D'utilisation

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Thermodynamic defrosting

If the ambient air is very humid (rain, fog, etc.) and the air temperature is relatively cool (below 15° C), frost can
rapidly accumulate on the evaporator fins and thus hinder recovery of calories by the heat transfer fluid.
The frost must be melted before this phenomenon becomes too pronounced.
All BWT heat pumps are equipped with an automatic thermodynamic cycle inversion defrosting system:
When the temperature sensor located on the fluid circuit at the evaporator inlet detects an abnormal drop in
temperature, the regulator causes a 4-way valve to deviate the circulation of gas in the system as described below:
It should be noted that BWT heat pumps will decrease the speed of rotation of the compressor and the fan in order
to decrease the frequency of defrosting
The roles of the evaporator and condenser are reversed: The fluid brings calories to the fin heat exchanger to melt the
ice. The fan remains stopped while the system is defrosting. When the temperature detected by the sensor increases,
defrosting is finished and the 4-way valve switches back to the normal cycle.
CHAUFFAGE & DÉSHUMIDIFICATION
phases.
Compressor
compresseur
Normal cycle
Cycle normal
Expansion
Détendeur
chamber
Compressor
compresseur
Cycle inversé
Inverted cycle
Expansion
Détendeur
chamber
2020/11 - Indice de révision : I - Code : 33340
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