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Evaporator Controllers

Evaporators absorb heat from space in a refrigeration unit and remove or maintain the humidity in that space. The primary focus of the Hench Control evaporator controller is to satisfy the zone temperature, which is established by a set point entered by the operator. The evaporator controller then works on saving energy by cycling the fans on/off, controlling the defrost cycles and the length of time the evaporator can stay in defrost mode. The evaporator controller module reacts with the condenser controller to raise discharge pressure for hot gas defrosts.

1T15 – One Temperature, Fifteen Zone Evaporator Controller
2T8 – Two Temperature, Eight Zone Evaporator Controller
2S2T8 – Two Speed, Two Temperature, Eight Zone Evaporator Controller
2T8V – Two Temperature, Eight Zone Variable Speed Evaporator Controller
3T8 – Three Temperature, Eight Zone Evaporator Controller
3T8B – Three Temperature, Eight Zone Blast Freezer Evaporator Controller
2T1 – Two Temperature, One Zone Evaporator Controller (MiniVap)

Temperature Sensors
-Liquid and/or Hot Gas
-Return Air/Probe


Defrost Types (Air vs. Hot Gas)

Key Benefits:

  • Works with compressor controller’s Energy Miser™ to raise suction pressure when loads are light, saving energy.
  • Allows fan cycling for energy savings when possible.
  • Controls up to eight evaporator zone temps and defrost sequences.
  • Displays eight evaporator zone return air temps.
  • Displays eight evaporator liquid line temps.
  • All defrost parameters are password protected, individually selectable for each zone.
  • Defrost start time is determined by amount of time the liquid solenoid is energized since last defrost.
  • Defrost stop time is determined by hot gas exit temp plus variable time delay, backed up by adjustable maximum time period.
  • Allows shutting down neighboring evaporator during defrost.
  • Defrost Blackout Table defines time when defrost is not allowed for each evaporator on a seven day basis.
  • Displays run time percent usage status for each evaporator.
  • Can be operated in heating mode for dock heating.
  • Logs run time hours for each evaporator.
  • Allows individual time offset of zone temp set points.
  • Logs all defrosts.
  • Limits number of evaporators defrosting at same time.
  • Defrost control scheme greatly reduces energy usage over standard time-clock systems.
  • Controls liquid solenoid, hot gas solenoid, suction stop valve and bleed valve.
  • Simple change of evaporator control parameters.
  • Two-speed fan version is also available (2S2T8).
  • Variable-speed fan version is also available (2T8V).
  • 3T8 version is also available, which is identical to 2T8, except it also measures discharge air temp, allows defrost initiation based on air temp drop, with cumulative cooling time backup.