The cost of refrigerant and regulatory compliance in the next five years will become as commercially important to vessel operations as regulations governing sulphur emissions are today, warns Robert Chesters, Managing Director Oceanic Technical Solutions.

“If shipowners fail to make their plants gas-tight, they could face refrigerant cost increases of up to 20% when stringent EU Regulations on Fluorinated Greenhouse Gases (F-Gas) enter in to force in 2020,” he says.

From now until 2030 there will be a phased reduction of the amount of virgin ozone-depleting hydrochlorofluorocarbons (HFC) placed onto the market. HFCs with a global warming potential (GWP) of 2,500 or more will be prohibited from January 2020 in new systems and for topping up of existing systems, although recycled refrigerants will be permitted until 2030.
“Compared to the outlawed R22 refrigerant, which cost around US$3/kg, new refrigerants, such as R404a, can be as much as $25/kg. But this is likely to be dwarfed by the cost of the next generation hydrocarbon-type refrigerants manufacturers are developing to meet the new requirements, making refrigerant a commodity that really should be retained.

“With a typical Air Conditioning (AC) plant aboard an LNG carrier needing a refrigerant charge of 600kg, refrigerant costs could escalate if the plant is not efficiently maintained. Owners must be aware that refrigerant is not a consumable in the same way as, say, lubricating oil, and should not need to be replaced. If systems are being constantly recharged then there’s a problem.”

Chesters says that for many reasons the refrigeration plant currently falls low on the list of maintenance priorities but this will become a compliance issue within the next few years as owners become mandated to reduce refrigerant leak rates – as much as 90% in some cases. This will mean regular leak testing and greater preventative maintenance measures are required.

“Owners do need to look now at how the F-Gas rules will affect the bottom line. If they are already spending thousands of dollars on refrigerant, then this needless expense will certainly increase by 2020. But if refrigerant loss is not dealt with the cost of compliance will far outweigh the amount owners are currently paying for refrigerant.”
With the anticipated increase in the cost of refrigerants the only guaranteed way to reduce refrigerant costs is containment. Owners can do a lot to reduce their refrigerant consumption by installing fixed leak detection systems, carrying out routine leak testing onboard and implementing full refrigerant reduction programmes.

Chesters went on to highlight that recent marine refrigeration inspections carried out by Oceanic engineers suggests in some cases even basic maintenance is not being carried out. “We found that some vessels were experiencing repeat failures and a significant loss of refrigerant to atmosphere due simply to worn valve gaskets and ‘O’ rings, while other leaks were reoccurring because temporary repairs were being incorrectly regarded as a permanent fix.”
Chesters also noted that some operators were running their plants with only 50% charge to limit the impact of increased refrigerant loss due to leaks and system faults and reduce costs.

“But this is a false economy as it results in increased energy consumption, increased cool down time, increased wear on main system components and in some cases premature compressor failure.”

The UK-based specialist also draws attention to hermetically sealed compressors usually found in packaged AC units. Dave Lloyd, Oceanic Technical Solutions’ Technical Director, explains: “If there is a compressor burn-out, the motor windings will produce an acid which if not cleaned up correctly will attack the internal windings of the new compressor which will result in subsequent compressor failure. We have found this on a number of vessels suffering repeat compressor failures, but this can be avoided with the correct system clean up and burn-out kits.

“Generally, it is the lack of available time to carry out effective maintenance that is hampering refrigeration plant optimisation and this will become more acute as this part of ship falls under increasing regulatory scrutiny.”

Chesters attests: “The new F-Gas Rules will place marine refrigeration high on the environmental agenda in the same way that MARPOL Annex VI and the Ballast Water Convention has changed the way in which vessels operate. The priority is on containment to carry out full plant inspections and optimise maintenance regimes, but this has to be proactive rather than reactive if owners are to reduce refrigerant consumption, emissions and associated costs.”

Oceanic Technical Solutions recently carried out extensive inspections of refrigeration plants aboard three NYK-LNG Vessels and 15 MOL LNG operated LNG carriers, and is now planning to carry out remedial modifications for these vessels.