FEAT RE FEA ATURE


HVACHVAC FLAMMABILITY STANDARDS AND 2L


FLAMMABILITY STANDARDS AND 2L REFRIGERANT INTRODUCTION Stuart Corr, techno commercial director of refrigerant gases


manufacturer and supplier,, Mexichem, discusses how the issue of refrigerant flammability relates to the use of reduced GWP


nufacturer and suppl


of refrigerant flam bility relates to the use of reduced G he regulation of fluorinated


refrigerants has now arrived here in Europe through theMobile Air Conditioning (MAC) Directive, for


T


automotive air conditioning, along with the F-Gas Regulation for all other


refrigerant applications. Over the last few years, chemicalmanufacturers have been looking to develop reduced GWP products that are capable ofmeeting the


requirements of these regulations and, whichmaintain the high levels of safety and efficiency we have come to expect fromhydrofluorocarbon refrigerants. We are in a position where the


refrigeration and air conditioning industries have a number of options available to them across the range of application sectors and many of the equipmentmanufacturers have active programs to thoroughly


investigate the performance and reliability of these alternatives and to optimise systemperformance based on the properties of the new flui ds .


THE NEW AL HE NEWALTERNA LTERNATIVES ATIVES


As withmany of the higher GWP products they are to replace, for examp e -404A, many of the new alternatives proposed are blended HFCs. The building blocks for these alternatives include the


l R


hydrofluoroolefins (HFOs) as well as the more familiar lower GWP fluids such as R- 32 and R-152a. All of these components are flammable, falling into the ASHRA 2L safety categories.Whilst they can be blended with non-flammable components in order to achieve non-flammability, for themaj


RAE 2 Figure 2: Figure 2: ajority of air conditi oning and


refrigeration applications, it is an unfortunate fact that the lowest GWP products will tend to be flammable to a degree,mostly falling within the ASHRA 2L category.


RAE


The industry is then faced with a choice: to use the lowest GWP fluid and accept a degree of flammability or to accept a higher GWP in order tomaintain non- flammability. Central to this choice is how tomeet the GWP regulatory requirements whilstmaint ia ning a high degree of safety? In some circumstances, the choice is made for us by the regulations. For


example theMAC directive requires use of refrigerant GWP below 150 and with the exception of CO2, there are no viable non- flammable candidates. Similarly looking ahead to alternatives for R-410A in smaller


20 20 SU SUMMER 201 ER 2016 | ENERG MANAGEMEN ENERGY MANAGEMENT


reviewed in order to address 2L refrigerants


An overview of some of the regulations and codes that are either under current review or which may need to be reviewed in order to address 2L refrigerants


An overview of some of


which may need to b under current review codes that are either the regulations and


or e


Stuart Corr, techno com ercial director of refrigerant gases r Mexichem, discusses how the issue


With the introduction of the 2L


flammability category in 2010, it was recognised that there was a group o f


Figure 1: Figure 1:


The internationally recognised A


he internationally recognised ASHRAE classificatclassification systemion system


(<3kg charge) single-split a/c systems, the F-Gas Regulation imposes a GWP limit of 750 and again there are no viable non- flammable candidates identified to date with R-32, and blends based on R-32, coming to the fore.


The first step towards introduction of a refrigerant is to determine the


flammability and toxicity classification for the fluid. This ismost commonly through the internationally recognised ASHRA classification system(figure 1). Whilst this process is essenti ally complete for theMAC sector, the


RAE


stationary applications aremore complex. In order to understand the ran applicability of a refrigerant, it


is necessary ge of


to consider a range of national and supra- national regulations. These regulations principally relate to the safe use of the refrigerant in a range of application sectors and govern aspects of equipment design, location and installation requirements. These regulations are generall y based on the refrigerant safety classification or the data used to obtain that classification, for example flammability limits.


Whilst highly flammable hydrocarbon refrigerants and the less-flammable ammonia have been used for a number of


refrigerants that whilst flammable, had the potential for lower risk in use than the more flammable hydrocarbons.Whilst current standards and codes provide safe boundaries for the use of flammable refrigerants,most do not yet recognise the 2L category. Accordingly, if 2L refrigerants are to be used in current equipment and environments, theymust be treated as if they were category 2. Under the current EN378 themaximumcharge for propan e in a wall-mounted indoor split a/c unit in a 3m-square roomis around 0.23kg whilst that for R-32 is around 3.08kg. Whilst this is still potentially very


attractive for 2L fluids in some application sectors, there are other regulations,many of themat a National level, that place more severe limitations on their use. For example both Italy and France currently prohibit the use of flammable refrigerants in roomair conditioners.


EN378 is currently under revision t o


incorporate and provide new limits for the 2L classification and is expected to issue in late spring 2016.


If we are to exploitmany of the low GWP fluids to theirmaximumextent, we need to understand how widely applicable they are, we need to understand how regulations should be amended to


incorporate the new classification whilst


practitioner safety. F i criticallymaintaining


gure 2 provides a n end-user and


overview of some of the regulations and codes that are either under current review or whichmay need to be reviewed in order to address 2L refrigerants.


Any amendment of standards and


building codesmust be undertaken with a significant degree of conserv respect to safety. Fur


thermore,many of rvatismwith


these codes and standards are only


reissued on a three-yearly or so basis and with a degree of interdependence. As a result it will be a number of years befor e the potential for 2L fluids to provide low GWP solutions across a range of sectors will become clear.


, Mexichem UK


www.mexichemfluor.com T: 01928 518880


www.mexichemfluor.com


years,most in relatively small domestic refrigeration applications or in industrial applications, the industry has generally relied on the use of non-flammable fluids to ensure a high degree of safety across a wide range of applications and operating environments.


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