A LTERNATIVE A GENTS
Testing of the new alternative agents and technologies mentioned in the 2010 HTOC Assessment Report continues.
Ongoing advancements in pyrotechnic products aim to produce nitrogen or nitrogen-water vapor mixtures with minimal particulate matter, specifically designed for total flooding fire extinguishing applications.
The development and testing of the unsaturated hydrobromofluorocarbon (HBFC) 3,3,3-trifluoro-2- bromo-prop-1-ene for use as a halon 1211 replacement in the aviation industry continues
Performance testing was carried out in 2011; minimum performance test requirements were passed in accordance with the International Aircraft Systems Fire Protection Working Group Minimum
Performance Standard (MPS) for portable extinguishers Values for ODP (0.005) and 100-year GWP (0.003) have been recently published Toxicology testing is planned for 2012
A new fluoroketone is being developed to replace halon 1211 and potentially halon 2402 in streaming applications In early 2012, the manufacturer was informed that the product review under the United States Environmental Protection Agency's Significant New Alternatives Policy (SNAP) program was completed, with an acceptability listing awaiting final rulemaking.
Innovative, non-corrosive, and low-toxicity water-based agents, enhanced with various additives, are being assessed for their ability to reach extremely low freezing points of -70°C without relying on glycols A specific formulation was tested in military vehicle and aviation applications in 2011, and the results are currently undergoing evaluation.
A fire protection systems integrator is introducing a non-pyrotechnic aerosol solution designed for aircraft engine nacelle and auxiliary power unit applications The product has successfully passed all necessary MPS tests, and the SNAP review is complete, with an acceptability listing awaiting final rulemaking Additionally, a full-scale demonstration of the aircraft engine fire extinguishing system is scheduled for 2012.
A chemical manufacturer has withdrawn its application for unsaturated HFC compounds, originally intended for use as a total flooding fire extinguishing agent, from the National Fire Protection Association’s 2001 Standard Although the product development is complete, concerns regarding supply may delay its commercialization for at least another two years.
H ALON 1301 U SE AS A F EEDSTOCK
Halon 1301 (CF3Br) is still being manufactured in China and France, primarily as a feedstock for the pesticide Fipronil In France, production levels are consistent at around 400 metric tons annually, while China's production has fluctuated over the past six years but is now thought to be stable However, the Halon Technical Options Committee (HTOC) does not have access to the latest production figures.
H ALON R ECOVERY AND R ECYCLING IN A RTICLE 5 C OUNTRIES
Indian users have successfully sourced adequate supplies of halon 1301 and halon 1211 from both domestic and international recycling companies Additionally, halon 2402 is now readily available due to its extraction from shipbreaking operations in India.
China has reclassified halons recovered from decommissioned equipment, no longer labeling them as hazardous wastes The country is advancing its recovery and recycling initiatives, with around 1,900 metric tons of halon 1211 produced before 2006 still available for use Despite this availability, China's current consumption of halon 1211 is only about 20%.
Despite the global shortage of halon 1211, it remains uncertain if this material can be exported in bulk Stakeholders should explore potential solutions to address this issue effectively.
Halon recycling and banking in the Middle East face significant challenges, with the sole operational bank located in Jordan potentially unsustainable due to low throughput Stakeholders should engage the regional network of ozone officers to explore the establishment of regional banking arrangements, ensuring a reliable supply of halons in the region This strategy could also benefit other regions encountering similar issues.
C ONTAMINATED R ECYCLED H ALONS
The HTOC previously reported that contaminated halon was supplied for aviation fire extinguishers, but prompt actions by industry and regulators ensured aircraft safety was maintained This incident prompted a review of recycled halon standards and purity testing methods Over the past year, the HTOC has collaborated with ASTM International to update the halon 1301 standard D5632 To mitigate risks such as increased agent toxicity and reduced fire extinguishing performance, the HTOC strongly recommends strict adherence to this and other international halon specifications and standards.
U PDATE ON THE R ESPONSE TO D ECISION XXI/7
The HTOC is collaborating with the International Civil Aviation Organization (ICAO) to mandate the phase-out of halon use in new aircraft On June 13, 2011, the ICAO Council endorsed the HTOC's proposals to amend Annex 6 of the Chicago Convention, which governs aircraft operations.
Aircraft, Part I — International Commercial Air Transport — Aeroplanes, Part II — International General Aviation — Aeroplanes and Part III — International Operations — Helicopters and Annex 8
— Airworthiness of Aircraft to establish requirements and timeframes for the replacement of halon fire extinguishing agents The Council approved the following:
Amendments to Annex 6, Parts I, II, and III were implemented on December 15, 2011, mandating the use of halon alternatives for lavatory fire extinguishing systems in in-production aircraft, with a compliance deadline of December 31, 2011 Additionally, the regulations require the adoption of halon alternatives for hand-held extinguishers in in-production aircraft, with an implementation deadline set for December 31, 2016.
Amendments to Annex 8, effective December 31, 2011, mandate the use of halon alternatives for fire extinguishing systems in engines and auxiliary power units of newly designed aircraft, with full implementation required by December 31, 2014.
ICAO will be sending a letter to its contracting States requesting information on halon needs and halon supplies
Contracting States are required to inform ICAO about their compliance with the amended Chicago Convention requirements by the specified deadlines An update will be provided by the HTOC at the 2012 OEWG.
The HTOC is committed to collaborating with ICAO to set a phase-out date for halon use in cargo bays of new aircraft designs and to assess the halon stock levels within the aviation industry.
HTOC M EMBERSHIP
In line with Decision XXIII/10, the HTOC has initiated the re-nomination process for its members, planning to stagger this process annually over the next three years In 2011, two non-Article 5 members resigned due to changes in their employment roles, but the Committee has since welcomed two new non-Article 5 members with expertise in aviation fire protection Currently, the HTOC is on the lookout for an expert in military fire protection within the European sector.
6 2012 Refrigeration, AC and Heat Pumps TOC (RTOC) Progress
In August 2011, the Refrigeration TOC convened in Prague alongside the IIR Congress to initiate discussions on membership and the framework for the RTOC 2014 Assessment report Preliminary conclusions were reached during this meeting, with plans to reconvene in May 2012 to finalize the membership composition, chapter outlines, and deadlines.
The 2012 RTOC Progress Report below is presented following the chapter subdivision of the RTOC
The 2010 Assessment Report, encompassing subchapters 6.1 to 6.9, was meticulously drafted by the RTOC Chapter Lead Authors and subsequently underwent multiple rounds of review and redrafting to ensure consistency and accuracy, as detailed in the TEAP and TOC membership lists found in Annex I of Chapter 11.
R EFRIGERANTS
Since the 2010 RTOC Assessment Report, several new refrigerants have been introduced for use in both new equipment and as service fluids for maintaining or converting existing systems Among these, five have received standardized designations and safety classifications, including R-407F.
The article discusses various refrigerants, including R-32/125/134a, R-442A, R-511A, R-512A, R-1234ze(E), and R-443A, highlighting their specific compositions and percentages R-443A is currently under public review for a standardized designation and safety classification, though these assignments remain provisional Additionally, it notes that some refrigerants have been commercialized without obtaining standard designations or safety classifications.
The ongoing development of new refrigerants focuses on hydrofluorocarbons (HFCs) and non-halogenated alternatives, prioritizing those with minimal ozone depletion potential (ODP) and low global warming potential (GWP) Efforts continue to create additional refrigerants and blend components to meet the scheduled phase-outs of ozone-depleting substances (ODSs) The 2010 RTOC Assessment indicates a shift towards low-flammability refrigerants, prompting the industry and governments to establish measures that support their safe use, particularly for refrigerants classified as A2L, which are characterized by lower toxicity, reduced flammability, and a lower heat of combustion.
Ongoing research aims to enhance the physical, safety, and environmental data of refrigerants, facilitating better screening and optimizing equipment performance This includes expanding knowledge on heat transfer, thermophysical properties, stability, compatibility, and other engineering data essential for designing efficient and durable equipment Recent patent applications indicate a growing focus on incorporating additives in refrigerants and lubricants to improve chemical stability against common construction materials and contaminants like air and moisture.
The chapter-update summaries that follow elaborate on progress in evaluation, selection, and introduction of substitute refrigerants for specific applications.
The status of certain new refrigerants, as well as additional blends expected to be designated and have safety applications this year, is subject to change The information provided is currently fluid and will be updated in future RTOC reports to reflect these developments.
D OMESTIC R EFRIGERATION
Since the 2010 Assessment, no major new technologies have emerged for domestic refrigeration, with HFC-134a and HC-600a remaining the top refrigerant choices for new production A small fraction of global output utilizes alternative refrigerants like HFC-152a and HC-290/HC-600a mixtures Current product development emphasizes enhanced energy efficiency, incorporating advanced components such as variable speed compressors and vacuum insulation panels The adoption of electronic controls further optimizes energy use by preventing single-point optimization under high-stress energy label conditions Efforts are underway to redesign products for a smoother transition from HFC-134a to HC-600a in select countries, and initial assessments for replacing HFC-134a with HFC-1234yf have commenced.
Recent regulatory changes have eased the use of flammable refrigerants, highlighted by the U.S EPA's approval of a field service process for their recovery U.S law mandates the recovery of all refrigerants during the servicing or disposal of domestic refrigerators, and this new approval eliminates a significant barrier to the adoption of flammable refrigerants Additionally, the regulatory evaluation of HFC-1234yf is now underway in the U.S.
C OMMERCIAL REFRIGERATION
Commercial refrigeration encompasses a diverse array of equipment, featuring various refrigeration capacities, designs, and refrigerant options Depending on the specific system, the refrigerant charge can range from several hundred grams to several hundred kilograms.
Since the 2010 Assessment, the options for refrigeration systems have remained largely the same, influenced by equipment size and evaporation temperature HFC-134a continues to be the favored refrigerant for small equipment due to its relatively low volumetric capacity In contrast, HCFC-22 and R-404A are utilized in larger commercial systems and in smaller systems designed for freezing applications, particularly those operating at evaporation temperatures of -35°C or lower.
The phase-out of HCFC-22 in Europe has led to a broader range of refrigerant options, including hydrocarbons like HC-600a and HC-290, R-744, and intermediate blends such as R-422D and R-427A, alongside traditional HFCs like HFC-134a and R-404A The selection of these alternatives hinges on factors such as global warming potential (GWP), safety, and energy efficiency Additionally, there is a growing trend towards using HFC-1234yf, either as a standalone refrigerant or within new blends Moreover, the adoption of indirect systems, which significantly reduce refrigerant charges by 50% to 75%, is on the rise, particularly in large supermarkets.
Hot climates with high ambient temperatures lead to high condensing temperatures and thus high condensing pressures Those high pressures and temperatures have several consequences:
COPs of medium and low temperature commercial systems are 20 to 25% lower in hot climates compared to moderate climates (ambient temperatures).
In low-temperature applications, such as frozen food storage, compressors often experience high discharge temperatures To manage this issue, liquid injection is necessary, either at the suction port or at an intermediate stage when utilizing HCFC-22.
Economizers are not widely adopted in commercial refrigeration due to high costs and a preference for traditional designs However, for low-temperature industrial applications, particularly in the food industry, two-stage systems are favored for their energy efficiency and reliability.
Discharge temperature and pressure constraints in hot climates lead to the choice of “medium pressure” refrigerant such as HFC-134a or HFC-1234yf for single stage systems Except for HC-290
Due to safety concerns, large systems face charge limitations, resulting in a shortage of low-GWP refrigerants with sufficient refrigeration capacity to effectively replace R-404A or HCFC-22 in single-stage refrigeration systems.
L ARGE SYSTEMS
The large systems market comprises three main segments: industrial refrigeration, industrial air-conditioning, and large heat pumps Most refrigeration and air-conditioning systems utilize R-717 or HCFC-22, where permitted In the large heat pump sector, R-717 systems typically employ screw or reciprocating compressors, while HFC-134a systems utilize centrifugal compressors.
The 2010 Assessment highlighted various issues concerning R-717, providing detailed regional insights into its usage The acceptance of R-717 as a refrigerant is significantly shaped by national regulations, which may impose restrictions on its application, limit quantities in systems, and mandate specific documentation for installation and maintenance Nonetheless, stringent regulations do not preclude the use of R-717; for instance, the United States enforces rigorous compliance with system design, maintenance, and record-keeping standards.
R-717 is widely accepted in the industrial sector, despite regulations mandating the reporting of any leak over 45 kg to a national database within 15 minutes of discovery In Canada, similar regulations exist, but they also require a full-time technician on-site for systems with compressor power exceeding 25 kW, which poses a significant cost barrier for all but the largest systems Moreover, comparable differences in regulations can be observed among European countries.
Germany enforces stringent regulations regarding large installations, particularly those exceeding a 150 kg load, necessitating government approval and imposing distance limitations from occupied buildings In contrast, such strict measures are less prevalent in France, where regulatory frameworks differ significantly.
In regions where regulations limit the use of R-717 or where there are other factors necessitating reduced on-site quantities, cascade systems utilizing R-744 or secondary heat transfer fluids have been adopted While HFC refrigerants have seen limited use, HFC-134a has been utilized primarily in large heat pumps, with the high cost of refrigerants being a significant barrier to broader adoption.
For Article 5 countries, HCFC-22 was historically the most common refrigerant in places where R-
R-717 has often been deemed too dangerous or complex compared to cheaper and safer alternatives like HCFC-22 and R-502, leading to a significant presence of ODS refrigerants in large systems, particularly in Article 5 countries where HCFC phase-out is incomplete Although there is a growing recognition that HFCs do not effectively replace HCFC-22 in large systems due to their inefficiency, higher costs, and the need for larger compressors or increased pressures, R-717 systems face challenges in widespread acceptance However, advancements in simple, automatic, low-charge systems over the past two decades may facilitate the adoption of R-717 in Article 5 countries and regions with stringent regulations To further ease the transition away from ODS refrigerants, some countries may need to amend their laws to alleviate the financial burden associated with this shift.
T RANSPORT REFRIGERATION
Most new transport refrigeration systems still rely on HFC refrigerants in vapor compression cycles While HCFC-22 has been entirely phased out in intermodal marine containers worldwide and in road transport in developed nations, it remains in use on ships and as a retrofit refrigerant in road transport in developing countries Although there are alternative refrigeration systems, their prevalence is minimal.
In 2011, the European Commission initiated a public consultation to explore various policy options for revising the EU regulation on fluorinated gases (F-Gas Regulation), with a specific focus on refrigerated transport A preliminary assessment of the proposal is anticipated in 2012, while the final regulation is expected to be adopted by the end of 2013.
Two global manufacturers have introduced marine and trailer refrigeration units using R-744 at exhibitions, initiating field tests Additionally, hydrocarbons are undergoing testing in trucks and home delivery vans across the UK and Germany While the potential of unsaturated fluorocarbons like HFC-1234yf is being investigated, no prototype equipment has been unveiled so far.
In 2011, safety concerns arose with various marine container brands due to three reported explosions linked to refrigerant imitation added during servicing in Vietnam This incident led to the docking of hundreds of containers and caused port workers to refuse work on specific vessels, highlighting the urgent need for affordable and safe working fluids in global trade.
In recent years, the shipping industry has explored alternatives to HCFC-22, prompting the European Commission to commission CE Delft for a research project focused on reducing greenhouse gas emissions from international maritime transport The findings of the CE report have sparked discussions at the Vessel Operators Forum, with some operators beginning to implement the recommended systems in new and retrofitted vessels However, cost-sensitive segments of the industry have temporarily dismissed the project's conclusions, opting to continue with HFC-based retrofits instead.
A IR - TO - AIR AIR CONDITIONERS AND HEAT PUMPS
Air conditioners and air-to-air heat pumps, with capacities typically between 2.0 kW and 35 kW (and in some instances up to 420 kW), represent a major segment of the global air conditioning market It is important to note that nearly all units produced before 2000 utilized HCFC-22 as their refrigerant.
As of 2012, the installed base of HCFC-22 units has surpassed 1.5 million tonnes, with around 75% of these units utilizing HCFC-22 Additionally, global demand for HFCs accounts for approximately 20% of the total refrigerant demand in these product categories, reflecting significant shifts in refrigerant usage since the 2010 Assessment.
Many Article 5 countries still rely on HCFC-22 as the main refrigerant for air conditioning, but several key producing nations in Asia, the Middle East, and South America are beginning to take steps towards adopting non-ODS alternatives.
R-410A, an HFC-based refrigerant blend, is the leading alternative to HCFC-22 in air conditioning systems, while the use of R-407C in new designs is declining significantly Additionally, HC-290 is being adopted for applications with low refrigerant charges as a substitute for HCFC-22 Looking ahead, HFC-32, R-744, and potentially HFC-161 are expected to emerge as viable options in the refrigerant market.
Air conditioners utilizing R-410A, along with R-407C to a lesser extent, are commonly found in most non-Article 5 countries, while several Article 5 countries, particularly China, are also manufacturing R-410A equipment The growing export market in China has spurred demand for these units; however, they are generally not available for sale in the domestic market due to their higher price.
In addition to the high GWP HFCs (R-410A and R-407C), there are several low and medium GWP alternatives being considered as replacements for HCFC-22 in Article 5 countries These include HC-
290, HC-1270, R-744 as well as HFC-161 (low GWP) and HFC-32 (medium GWP) Apart from R-
744, these are flammable and will need to be applied in accordance with an appropriate safety
The IEC-60335-2-40 standard sets maximum charge levels and specific construction requirements for refrigerants, while national regulations in various countries impose controls on flammable refrigerants Some smaller nations are even banning the import of HFC-containing air conditioners Additionally, current standards limit the allowable charge of R-744 due to its physiological effects, with most regulations restricting the refrigerant charge quantity in occupied spaces to ensure safety.
HC-290 and HC-1270, both with a Global Warming Potential (GWP) of less than 20, are primarily suited for systems with smaller charge sizes due to their higher flammability classification (class 3) These refrigerants operate at pressures and capacities comparable to HCFC-22, offering at least the same level of efficiency Currently, several manufacturers in China and India are launching split air conditioners charged with HC-290.
R-744, with a Global Warming Potential (GWP) of 1, is recognized for its limited use in air conditioning systems within Article 5 countries Despite its favorable characteristics as a refrigerant, R-744's low critical temperature leads to decreased efficiency when ambient temperatures rise above approximately 30°C While various cycle enhancements and additional components can be implemented to boost efficiency in these conditions, they may negatively impact the overall system cost.
HFC-161, with a GWP of 12, is being evaluated for systems with smaller charge sizes due to its higher flammability classification (class 3), while maintaining operating pressure and capacity comparable to HCFC-22, and demonstrating at least equal efficiency In contrast, HFC-32, classified as mildly flammable (class 2L) and possessing a GWP of 717, is under consideration for various air conditioning applications, offering similar or improved efficiency compared to R-410A, along with operating pressure and capacity that align closely with R-410A.
Low GWP single component HFCs, including HFC-1234yf (GWP = 4) and HFC-152a (GWP = 130), are not expected to replace HCFC-22 in air conditioning systems due to their limited volumetric refrigerating capacity.
Various refrigerant mixtures are being developed for air conditioning, including HFC-32, HFC-152a, HFC-161, HFC-1234yf, and HFC-1234ze These mixtures exhibit operating pressures and capacities similar to HCFC-22 or R-410A, with Global Warming Potentials (GWPs) ranging from 150 to around 1000 and varying flammability classifications, from non-flammable (class 1) to mildly flammable (class 2L) Some developments are aimed at enhancing performance under high ambient conditions However, these mixtures are not yet commercially available, and technical data remains undisclosed.
W ATER HEATING HEAT PUMPS
Heat pumps are categorized based on their heat source—air, water, or ground—and their heat sink, which can also be air or water This article focuses specifically on systems utilizing water as the sink, particularly heat pump water heaters that efficiently heat domestic water to temperatures ranging from 55 to 90 ºC Notably, air-to-water heat pumps have seen substantial growth in markets such as Japan, Europe, China, and Australia over the past five years, with sales forecasts indicating continued expansion in Japan, China, and Europe.
Efficient heat pumps play a crucial role in mitigating global warming by significantly lowering emissions compared to fossil fuel systems Their effectiveness is influenced by the heat pump's efficiency and the carbon emissions associated with electricity generation As electricity becomes increasingly decarbonized and heat pump efficiency improves, the positive environmental impact of these systems continues to grow.
Current refrigerant options for new heat pumps include R-410A, HFC-134a, HC-290, HC-600a, R-717, and R-744 HFC-134a and HFC blends like R-407C and R-410A are commonly utilized in new water and space heating heat pumps to replace HCFC-22, with R-407C requiring minimal product redesign and R-410A necessitating complete redesigns HC-290 shares similar properties with HCFC-22, aside from its flammability, but its use has decreased in the EU since 2004 due to the Pressure Equipment Directive Additionally, R-717 is recognized as a non-ODS refrigerant.
TEAP May 2012 Progress Report 57 and has a very low GWP, but it has higher toxicity and lower flammability characteristics R-717 is used mainly for large capacity systems (see section 6.4)
The development of R-744 heat pumps began in the 1990s, leading to the introduction of R-744 heat pump water heaters in Japan in 2001, primarily for heating bath and sanitary water While the current market for space heating heat pumps in commercial buildings, which utilize combined radiator and air heating systems, remains limited, R-744 is recognized as a promising refrigerant for future applications.
Future refrigerant options for new heat pumps include HFC-32, R-1234yf, R-1234ze, and their blends, offering lower global warming potential (GWP) HFC-32 is noted for its low flammability and reduced burning velocity, making it a safer alternative Additionally, heat pumps utilizing HFC-32 require a lower refrigerant charge compared to those using R-410A, enhancing their efficiency and environmental performance.
HFC-1234yf shares similar thermophysical properties with HFC-134a, but optimizing heat pumps for water and space heating that currently use HCFC-22, R-410A, or R-407C would require significant design modifications With low flammability and a low burning velocity, HFC-1234yf presents a promising alternative for applications relying on HFC-134a, particularly due to its low global warming potential (GWP).
The growing adoption of heat pumps is projected to result in higher refrigerant demands and emissions in the coming years However, it is crucial to highlight the significant opportunity to decrease CO2 emissions by substituting fossil fuel heating systems with energy-efficient heat pump systems.
C HILLERS
Chillers play a crucial role in providing comfort air conditioning for commercial buildings and complexes, working in conjunction with chilled water distribution and air handling systems They are also essential for cooling in various commercial and industrial settings, including data processing centers and electronics fabrication New chillers commonly utilize refrigerants like HFC-134a and R-410A with positive displacement compressors, while HCFC-22 is still in use in regions where the phase-down has not yet commenced In the positive-displacement category, scroll and screw chillers are the most prevalent, with limited production of reciprocating compressors focusing mainly on servicing existing chillers.
Since the 2010 Assessment, no new options for chillers have emerged; however, notable trends include the availability of chillers using R-717 or hydrocarbon refrigerants, such as HC-290, HC-600a, and HC-1270 These chillers are produced in smaller quantities than their HFC counterparts and necessitate careful consideration of flammability and, in the case of R-717, toxicity, as outlined in relevant safety codes and regulations.
The ongoing trend in chiller development focuses on enhancing both full-load and seasonal energy efficiency to mitigate global warming effects, comply with building energy regulations, and reduce operating costs Additionally, there is a growing market share for chillers designed for heat pump applications.
Alternative chiller refrigerants to Ozone-Depleting Substances (ODS) and high Global Warming Potential (GWP) options include R-717, hydrocarbons, R-744, HFC-32, and emerging low-GWP refrigerants like HFC-1234yf and HFC-1234ze(E) Various countries are currently conducting testing and evaluation programs for these low-GWP refrigerants, including the Low-GWP Alternative Refrigerants Evaluation Program by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) in the U.S., which plans to test six or more low-GWP refrigerants or blends in screw and centrifugal chillers Additionally, similar chiller tests have been carried out in Japan.
Several low-GWP refrigerants are categorized as A2L refrigerants, characterized by their low flammability and low burning velocity Concurrently, risk analyses and safety requirements for the use of these refrigerants in chiller applications are being developed alongside ongoing testing programs.
Absorption chillers utilizing ammonia-water or water-lithium bromide pairs serve as an effective alternative to traditional vapour-compression chillers, especially in scenarios where excess heat can be harnessed Ongoing advancements are being made in chillers that utilize solar hot water as their heat source, enhancing their efficiency and sustainability.
V EHICLE A IR C ONDITIONING
Over the past decade, car manufacturers have explored various refrigerant options for air conditioning systems in vehicles, focusing on R-744, HFC-152a, and HFC-1234yf, all of which have Global Warming Potentials (GWPs) below the EU's 150 threshold These alternatives can achieve fuel efficiency comparable to existing HFC-134a systems with proper hardware and control advancements The choice of HFC-1234yf as the preferred refrigerant was influenced by factors such as regulatory approval, cost-effectiveness, system reliability, and ease of servicing.
The future of refrigerants in bus and rail air conditioning systems remains uncertain, with R-744 emerging as a potential candidate However, the shift towards low-GWP refrigerants in these systems may closely mirror the trends established by automotive manufacturers.
Global car manufacturers have adopted HFC-1234yf as the new refrigerant for air conditioning systems in cars and light trucks, marking a significant shift since the 2010 Assessment These manufacturers are designing mobile air conditioning (MAC) systems to ensure compatibility with both HFC-1234yf and the existing HFC-134a refrigerant The U.S Environmental Protection Agency’s (EPA) Significant New Alternatives Policy (SNAP) program recognizes HFC-1234yf as an acceptable substitute for ozone-depleting substances in motor vehicle air conditioning, provided specific use conditions are met.
HFC-1234yf MVAC systems are required to comply with SAE J639 safety standards, which include essential features such as a flammable refrigerant warning label, a high-pressure compressor cutoff switch, pressure relief devices, and distinctive fittings.
Manufacturers must conduct Failure Mode and Effect Analysis (FMEA) as provided in SAE J1739
The California Air Resources Board of the California EPA predicts that widespread adoption of low GWP refrigerant technology will not occur until after 2017, primarily due to the high cost and limited availability of HFC-1234yf in the near future.
R-744 is recognized for its excellent heat pumping capabilities, making it a promising refrigerant for hybrid and battery-powered electric vehicles It is also emerging as a leading option for air conditioning systems in buses and trains, with ongoing fleet tests of R-744 systems being conducted in public transportation buses.
One large OEM still considers HFC-152a as a viable future option but has not moved further in this direction.
The use of hydrocarbons or blends of hydrocarbons as a refrigerant has also been considered but has not received support so far from vehicle manufacturers due to safety concerns.
A leading global chemical company has introduced two zeotropic HFC blends, which are anticipated to offer a competitive price and high availability in the future These blends, whose compositions remain undisclosed, exhibit thermophysical properties, environmental impact, and flammability levels similar to those of HFC-1234yf, making them promising alternatives in the market.
7 Use of refrigerants on ships – Decision XXIII/11
Decision XXIII/11, taken by the Parties at their 23rd Meeting mentions in paragraph (7) the following:
In its 2012 progress report, the Technology and Economic Assessment Panel is requested to summarize data on the use of ozone-depleting substances in ships This summary should include typical quantities used across various ship types, an estimation of the refrigerant bank on ships, and an assessment of emissions related to these substances.
TEAP and its RTOC have addressed the request by revisiting the information outlined in Chapter 6 of the RTOC Assessment Report, which focuses on transport refrigeration.
2010 and has supplemented it with some recent material The results are given below.
From a commercial and regulatory point of view, size and type are two key parameters that characterize ships.
The overall size of a ship is measured in terms of gross tonnage (GT) Nearly all vessels larger than
Vessels with a gross tonnage (GT) of 100 or more are equipped with refrigeration systems for food storage and air conditioning for passenger comfort While ships exceeding 100 GT are monitored by organizations like IHS Fairplay, classification societies and safety regulations such as the Safety of Life at Sea (SOLAS) convention primarily focus on medium and large vessels over 500 GT In contrast, ships under 100 GT typically utilize permanently sealed equipment, which minimizes the risk of refrigerant leaks, such as domestic refrigerators and self-contained air conditioners.
There are many types of vessels, each with coding systems tailored for analytical needs To address diverse requirements, IHS Fairplay has introduced a new coding system that identifies 318 vessel types (Statcode, level 5).
Air pollutant emissions from ships are covered by Annex VI of the Marine Pollution Convention, MARPOL 73/78, of the International Maritime Organization (IMO) MARPOL Annex VI (Regulation
12) prohibits new installations containing chlorofluorocarbons (CFCs) on all ships from May 19,
2005, but new installations containing HCFC refrigerants are permitted until January 1, 2020 As of February 29, 2012, there were 68 contracting states that represent 91 % of the world tonnage
The revised MARPOL Annex VI, effective July 1, 2010, mandates that all ships of 400 GT and above maintain a list of equipment containing ozone-depleting substances (ODS) and an ODS record book This requirement specifically pertains to rechargeable systems and excludes permanently sealed equipment The record book serves to track refrigerant usage and monitor potential leaks in the system.
Estimating the use of Ozone Depleting Substances (ODS) on ships requires analyzing the number of vessels and their average refrigerant charge, as a dedicated database is not yet available While refrigerant charge is generally correlated with the size and type of the vessel, specific data is currently lacking This information can potentially be sourced from shipyards or large fleet operators.
IHS Fairplay, the exclusive global issuer of the IMO numbering system, maintains a comprehensive Sea-web register with data on over 180,000 ships of 100 GT and above As of January 2011, the Review of Maritime Transport reported 103,392 seagoing commercial ships exceeding 100 GT Additionally, the Food and Agriculture Organization estimates around 50,000 fishing vessels of the same tonnage worldwide However, the types of approximately 30,000 vessels in the commercial Sea-web register remain unidentified without further access.
HCFC-22 has been the predominant refrigerant used in maritime applications, especially in ships built before 1999 With the phase-out of HCFC-22, many of these refrigeration systems are now transitioning to alternative refrigerants such as R-407C, R-417A, R-421A, and R-422D for aftermarket service Although the production and consumption of CFCs were prohibited in non-Article 5 countries starting in 1996 and in Article 5 countries by January 2010, some CFCs remain in use However, the existing stockpiles of CFCs are expected to diminish over the coming years.