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Direct Expansion HVAC

Category:relating to "Direct Expansion HVAC"

  • Proprietary & Special Technologies
  • Cleanroom Technologies
  • Renewal
  • Energy Solutions

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Low-cost and high control accuracy of ±1°C with the air-cooled type and of ±0.5°C with the water-cooled type

We have developed our direct-expansion HVAC that contains an inverter condensing unit and it is applicable to cleanrooms or temperature and humidity testing rooms where no central heating facility is equipped. In addition to the 24-hour non-stop air conditioning operation, it achieves low-cost and space-saving operations and enables you to maintain room atmosphere at an accuracy of ±1°C with an air-cooled type and ±0.5°C with a water-cooled type.


  • Excellent control accuracy of ±1°C with air-cooled type and of ±0.5°C with water-cooled type.
  • Non-stop and single-step control operation in response to cooling load in the range of 0 to 100%.
  • Cooling and re-heating with high-temperature refrigerant at the outlet of the compressor as a heating source.
    Reduces annual power consumption by 30% with its higher COP than the water-cooled type.
  • No cooling water pump or cushion tank is needed. It conserves space.
    Requires approximately 50% less space compared with the chiller type.


  • For rooms where 24-hour non-stop air conditioning is required
    General package air conditioning can be interrupted when the compressor shuts down
  • For small- to medium-size temperature and humidity testing rooms where there is no central heating (high efficiency heating source) facility is equipped
  • For outdoor air handling units requiring dew-point temperature control and reheat temperature control
  • For dry coil systems in a small- to medium-size cleanrooms (using a high-temperature condensing unit)
  • For air handling units requiring a low dew-point that a water-cooled type is not capable of providing (example: 3°C DP)

Direct expansion HVAC flow chart

Example of construction

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