Namibian summer heat puts NH3 coldstore to the test

By Alexandra Maratou, Jun 11, 2012, 09:06 2 minute reading

An ammonia refrigeration system for a fruit and vegetable storage facility in Namibia, which employs GEA Grasso piston compressors, has proved its effectiveness after operating in the African summer (November through March), meeting expectations with respect to energy efficiency. Using the natural refrigerant ammonia allowed for significant efficiency gains in the central refrigeration complex.

GEA Refrigeration Africa, a subsidiary of GEA Refrigeration Technologies designed and implemented a refrigeration system for a fruit and vegetable storage facility that was commissioned in September 2011 in Aussenkehr, Namibia, on behalf of the Dutch company Cool Fresh International BV.

The new storage complex comprises four halls, including sorting, consignment, and receipt of incoming fruit and vegetables through a cooling tunnel and is designed to store products such as grapes, melons, dates, and tomatoes cultivated as part of the Orange River Irrigation Project of the government Agricultural Ministry, and marketed by Cool Fresh.

GEA Grasso ammonia piston compressors assure produce freshness

The refrigeration needed for the halls is provide by:
  • 1 GEA Grasso G3.10 ammonia piston compressor and
  • 2 GEA Grasso G4.10 ammonia piston compressors

The compressors operate in single-stage mode to cool the halls, as required, to the required temperature of about 0°C to a maximum of 12°C. At hall temperatures around 8°C, they offer cooling duty up to 180 kW (G3.10) and 240 kW (G4.10). In the halls, cooling is provided by zinc-plated evaporators via air flow.

Special solution for freezing dates

Storage of the dates, which are harvested from February to April, required a special solution to enable them to be frozen in one of the halls until export. The refrigeration system operates in two stages (-28°C/0°C and 0°C/+35°C) to achieve the required temperature of -20°C in the hall. Special valve units enable switch-over between the two-stage mode for freezing and the single-stage cooling mode.

About GEA Refrigeration Technologies

GEA Refrigeration Technologies is a leading global group in industrial refrigeration. GEA designs, engineers, installs, and maintains innovative key components and technological solutions. Typical applications include cooling processes for the food and beverage industries, marine, oil and gas industries, buildings, as well as leisure facilities such as indoor ski centers and ice-skating rinks. 

Contact information 

If you would like to contact GEA Refrigeration Technologies for any enquiries, you may send a request to Winfried Recker directly.


By Alexandra Maratou

Jun 11, 2012, 09:06

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