System solution for Air Property Control

Case Study

General Motor, Shanghai China

ABS Manufacturing Plant, Delphi (General Motor), China

DDC Controller

Controlled Parameters

  • No. of AHUs : 3 nos.
  • Room temperature : 22°C+/-1.0°C
  • Room humidity : 50%RH+/-5%RH
  • Air circulating OA/RA : 10%/90%
  • Room pressure : 10-15 PA
  • Cleanliness class 100k

Room Temperature / Humidity Sensors with LCD Display

Nanyang Technological University, Singapore

NTU Media Resource Library The NTU Media Resources Library is a 600 square meter site that houses media materials such as books, videocassettes, audiocassettes, multimedia software, CDs, VCDs, DVDs, laser discs, slides, and maps in all subject areas.

It is separated into two rooms – a server room and a library. Both rooms are very sensitive to relative humidity fluctuation. The sensible and latent heat within the library is unpredictable. This is primarily caused by the external tropical climatic condition as well as an extensive movement of people within and out of the library. The original chilled water AHU cannot bring down the supply air dew point to maintain room condition at 22°C and 45%RH. The high variability in sensible and latent heat loading further exacerbate the problem.

Enercov worked with the owner to design a Total Solution using its HRUTM Series. The DDC Fuzzy Logic Controller accurately regulated the chilled water flow and the fan speed achieving a constant sensible and latent heat throughout the day inside the library. The supply air was cooled to its dew point of 9.5°C before recalibrating back to 22°C using the Hot Gas Reheat Coil. This allows precise air properties control without any heating elements or desiccant wheels.

In this System Solution design, Enercov also caters to its customer specific need for positive room pressure and 10% fresh air feeding to increase the oxygen level within the library. After the installation, the NTU Media library has an energy saving of 50% compared to its previous implementation which used the traditional desiccant wheel.

Nanyang Technological University, Singapore
Media Resource Library

DDC controller, Room Temperature / Humidity Sensors with LCD Display

Controlled Parameters

  • No. of AHUs : 1
  • Room temperature: 22°C+/-1.0°C
  • Room humidity: 45%RH+/-3%RH
  • % Air circulating OA/RA: 10%/90%
  • Room pressure: Positive

National University Hospital

Enercov’s equipment has been implemented at the National University Hospital (NUH)’s Operating Theatres. Each Operating Theatre has an area of about 65 meter square. The room requires precise temperature and humidity control for various different surgical procedures.

The room temperature can be adjusted by the surgeon between 18 to 25 degree Celsius. Typically, 18 degree Celsius is selected for long operation while 25 degree Celsius is selected for babies or infants care. The dew point can be adjusted and monitored for moisture control.

Controlled Parameters

  • No. of AHUs : 1
  • Room temperature: 18° to 25° C+/-1.0°C
  • Room dew point : 11° C+/-1.0°C
  • Fresh Air: 100%
  • Room pressure: Positive – 15 Pascal

Enercov selected the HRU Series equipment that uses direct expansion Reheat Coil to supply the required heat for precision air properties control. Without the usage of any Electric Heater, energy saving is at approximately 40%.

Using our patented DDC Fuzzy Logic Controller, Enercov is able to adjust air properties from 18 to 25 degree C within 20 mins, faster than any systems that are in the market today. Unlike Electric Heater System, Direct Expansion Reheat Coil does not produce any “burned smell”.

After installation of Enercov HRU Series equipment, NUH has an energy savings of about 40% for the Operating Theatre.