NH3/CO2 coldstore case study discussed at Dutch congress

By Sabine Lobnig, Dec 15, 2010, 12:45 2 minute reading

A congress held last week in the Netherlands discussed issues the RAC industry is facing, including the future HCFC phase-out that calls for plant retrofits or replacements. One case study highlighted the opportunities and difficulties encountered by a coldstore that replaced its HCFC22 system with an NH3/CO2 cascade one.

Organised by NL Agency in close cooperation with the NVKL (Dutch Refrigeration & Air-Conditioning Association), KNVvK (Royal Dutch Association of Cold) and VERAC (Association of suppliers of air conditioning equipment), “De Week van de Koude” (The Week of the Cold) brought together industry players to discuss latest issues in relation to cooling technologies.

Topics discussed included the phase-out of R22 - the most commonly used hydrochlorofluorocarbon (HCFC) in air conditioning and refrigeration across Europe -, developments with regards to cooling technologies, energy efficiency and sustainability issues as well as f-gas related legislative issues.

Phasing out HCFCs closer than (n)ever

Titled ‘Phasing out HCFCs closer than (n)ever’, a presentation provided by Peter van Dijk, of the Van Dijk’s Cothen coldstore for the storage of frozen products outlined the company’s experience with converting their plant from R22 to an ammonia/CO2 cascade system.

Constructed in 1980, the old HCFC22 plant was of a pump type system, using 7,000 kg of refrigerant. This was replaced by a new plant featuring:
  • NH3/CO2 cascade system
  • 2 ammonia compressors
  • 2 CO2 compressors
  • hot gas defrost
Reasons for opting for a new installation over a retrofit solution included the fact that there was no suitable blend for R22 pump systems available, and that the piping of the old system was in a poor condition and not suitable for higher pressure refrigerants. Moreover, a new installation encompassed energy saving opportunities.

However, at the time of installation the new technology was not yet an established one and as such there was lack of knowledge that resulted in a long 2-year (2003-2005) project preparation period as well as a 2-year use phase & adjustment (2005-2007) period.

Despite some difficulties, the NH3/CO2 cascade system is running reliably, encompassing 20-25% of energy savings and lower maintenance costs, rendering the coldstore owner a satisfied customer and “ready for the future” when HCFCs will be banned.

Background: forthcoming HCFC phase out

Driven by the Montreal Protocol, European legislation mandates the complete phase out of HCFCs in Europe as of 2015. As of January 2015, all HCFCs – both virgin as well as reclaimed or recycled – will be banned for servicing and maintaining existing systems. This means that topping-up of HCFC plants with refrigerant during service or maintenance will not be possible anymore. Plants will be able to continue operating so long as there are no accidental leaks, after the event of which plants will have to be retrofitted or replaced.

Preparing for the 2015 deadline, several building owners are already planning or implementing retrofits and replacements of HCFC equipment, with their replacement options ranging from hydrofluorocarbons (HFC) to natural refrigerants. 


By Sabine Lobnig

Dec 15, 2010, 12:45

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