Low GWP Refrigerants (No Fugitive Manufacturing Emissions)

[Max]

I’m looking at what impact low GWP refrigerants can have on a project. From what I can tell, bulk swapping R134a with R1234z results in increased GWP impacts. Positive GWP impacts are only found when selecting R1234z with no fugitive manufacturing emissions.
I’m keen to understand what the “no fugitive manufacturing emissions” means in our projects?
Should low GWP refrigerants make a positive GWP impact? Why would replacing R134a with R1234z increase GWP?

Also, there are a wide range of other low GWP refrigerants, e.g. R1233zd. But these are not listed in the available templates. Can anyone vouch for the embodied energy impacts of the different low GWP refrigerants and whether they are that dissimilar? Would R1234z be a suitable substitute for all low GWP HFO refrigerants?

[Richard Haynes]

Hi Max,

Good questions. Firstly there’s two parts to the refrigerant impacts. One is “Release”, that is, what happens to the refrigerant when it’s released. These are the direct affects (scope 1 in GHG accounting terminology) of releasing the refrigerant to the environment. This is equivalent to the emissions associated with combusting natural gas in a building (there’s literally resulting CO2 emissions at the actual building). This is usually where the largest impacts are. The other is the production impacts. If a “Low GWP” refrigerant takes a lot of energy to produce, or the supply chain results in a lot of fugitive emissions of high GWP gasses, the production impacts of that refrigerant may be quite high. This is what is driving the impacts of R1234z. Now, the refrigerant is still relatively new, and the production techniques are probably advanced beyond the EcoInvent data quality. Our data supplier (Life Cycle Strategies) noticed the high production impacts and investigated this. They related (largely) to fugitive emissions. He researched the current day production techniques and found evidence to suggest that fugitive emissions had been significantly reduced in the supply chain so he provided two materials, one with fugitive emissions and one without. Based on Life Cycle Strategies research, we would suggest using the “no fugitive emissions” version.

Your question is actually really timely. We are just releasing a new version of data with a wider selection of refrigerants and updated LCI impacts. This dataset should be available in a few days. If you’re interested in modelling refrigerants with greater accuracy please request V14 (edit: as of Dec 2021, the latest version of the data is v17) of the data for your project.

Rich

[Sam4167]

Thanks for the info Rich.

Just to clarify, you suggest using “no fugitive emissions” version for all refrigerants that this option is available for? Any particular refrigerants or situations that we should avoid this option?

[Richard Haynes]

Probably not. But I’ll raise this question with the data supplier as it’s a fairly important point for making a decision with confidence. Rich

[Pat4644]

Hi, to clarify, “no fugitive emissions” refers only to the emissions at manufacture rather than emissions from leakage and end of life which are specific to building equipment the gas is used in?

From what I can tell these impacts in etool are reported in B2/B3. However EN15978 and RICS Professional Statement makes particular reference to refrigerants reported in module B1. Can you clarify this??