Radiate
Why I was disappointed to see this new heat pump
Hi Folks,
I’m eager to get into the new year proper, and I hope you’ll stick with me. I’ve got plenty more lined up, ready to share.
You may recall that in the last newsletter I mentioned I’d been to see family over the break, including a stop to visit my father in-law. Some months back, he’d mentioned he was looking at upgrading his heat-pump. Knowing my interest in refrigerants and energy, he had asked my opinion on a replacement, which I duly gave. He took the suggestions seriously, and when I heard he had put the new unit in place I was quietly pleased. That was until I saw it.
The option he had originally presented to me, was from a well-respected manufacturer using a low-GWP natural refrigerant, R290. I gave it a big thumbs up, with the caveat that it also needed sizing correctly.
Stopping by on our recent trip, he proudly showed off his newly installed heat-pump. It was a good-looking unit, and reasonably well fitted, however I think my disappointment showed. Apparently, the contractor couldn’t supply the units using natural refrigerants for several months due to back orders. Hence, they had provided him an alternative unit with a ‘special gas’ that apparently was ‘just as good’.
I breathed out slowly.
“Special Gas”
The ‘special’ refrigerant gas was R32. A man-made, synthetic refrigerant and a fluorinated global-warming gas. In the contractor’s mind, it was likely special because it is not as bad as the gas in his old unit, R410a.
R410a has been popular in heat-pumps and many split air-conditioners for some time, however it has a relatively high global warming potential (GWP) of 2256*. So along comes R32 with a GWP of 771 and everybody thinks great – big reduction there.
Put aside for the moment that R410a is actually a blend made up of two other gases, one of which is R32... However, R32 on its own is a decent refrigerant. Its flammability is not really an issue when carefully handled and it performs efficiently in most scenarios.
But there are a couple of catches.
First. There are proposed changes to the EU f-gas regulations which would restrict the use of refrigerants with a GWP above 150, in domestic heat-pumps from 2027 (arguably still too high). In effect the gleaming new unit just installed is about to become outdated. The issue being the already limited availability of skilled contractors, and their associated servicing equipment, are likely to shift focus.
Second. There is the size of the charge (amount of refrigerant). The previous heat-pump had a charge of 2.5kg of R410a refrigerant giving a banked CO2e of 5.6 tons (the total ‘stored-up’ emissions in the refrigerant). The new R32 unit has a larger 4.2kg charge with a total banked CO2e of 3.2 tons. The gains not as big as you might expect. For context 3.2 tons of CO2 is roughly equivalent to driving a passenger vehicle half-way around the globe…
For me however, the real problem with R32 is it being a synthetic chemical refrigerant. In a net zero world these gases can never enter the atmosphere. And with end-of-life handling still poor and destruction levels so low we are just kicking the can further down the road.
And the atmospheric concentrations keep going up.
While we are talking industry limits. As an example, Singapore not long back introduced a GWP limit of 750 for domestic air-conditioners. I’m assuming based on the earlier IPCC reports which had R32 with a GWP of 677. However, in the most recent report, the warming impact of R32 has been updated to 771, above the recently announced limit. I’m sure this has led to a little bit of head-scratching.
We know there are no-longer any ‘ideal’ synthetic refrigerants. Going forward natural refrigerant R290 still looks like the best bet for domestic heat-pumps and AC from an overall environment perspective (when upstream and downstream impacts are all considered). Concerns over efficiency are unfounded as numerous reports have now established.
To re-iterate again, I’m all in favour of heat-pumps. However, large scale deployments of heat-pumps with synthetic refrigerants are going to leave us with an enormous polluting waste problem to deal with.
What would I have done in my father-in-law’s shoes given the onset of winter? Fair question.
For me a heat-pump is a long-term investment, 10-15 years, possibly more. Over that time there will be leaks and maintenance. I personally would have waited until an R290 unit was available. As he also has solar panels, he could have used some mobile electric storage heaters to hold over. Not ideal, but it would have avoided adding further to the polluting refrigerant banks. The ones that we are going to have to clean-up in the coming decades.
Agree, disagree? Feel free to drop a comment over on Linkedin.
*It can be a challenge keeping track of all the GWP figures as they are regularly updated based on the latest scientific efforts. I make an effort to keep on top of them and you can find a link to a table here. I’ve used IPCC AR6 values in the calculations above.
Where the F-Gas hides
Each week I provide an example of where f-gases are utilised, or used to produce something. They are present in more things than most people realise…
I like trains and will travel by them whenever I can (my journey across Turkey into Syria was especially memorable).
While on our recent family break, we stopped by a fantastic train museum in Mulhouse, France. I’d highly recommend it. I could’ve spent hours staring at the mechanical marvellousness of the steam locomotive drive systems.
Walking around the museum I began to consider where the f-gas might be hiding in the trains. As there were old and new, HFC refrigerant-based air-conditioning would be present in some carriages for sure. There was also a cut-away display. One of the excellent high-speed electric TGV trains, housing a large 25kV transformer. Highly likely (though not quite eyeballed as I couldn’t get close enough) to contain SF6 as a fluorinated insulating gas. We’ll cover transformers, switchgear and SF6 in upcoming editions…
There was also another location that cropped up in my subsequent reading. Made a little more challenging by my so-so technical French language skills.
Freon™️tanks or ‘enceintes fréon’.
Like their forebears, the TGVs are also a marvel of complex engineering. From what I can establish the electric drive systems of the early TGVs used banks of thyristors that required significant cooling. They were originally immersed in cylindrical cooling tanks using refrigerant R113. This fluorinated refrigerant however was a CFC and an ozone depleting substance which was banned in the 90s.
As a replacement they apparently moved to FC72 which is an inert, fully fluorinated liquid, which is also classed as a PFC (perfluorocarbon). While it is not ozone depleting, it does have a very high global warming value (GWP) of around 9000! Records suggest that over 40,000 of these cooling tanks were manufactured which is a decent bank of f-gas.
I’m not sure if they continue to be used in the current rolling-stock (possibly they have moved to glycol) so if there are any train geeks out there who might know, feel free to leave a comment.
Right, that’s all for this week and ‘till next time,
Adrian
p.s. Last week’s title track – Graffiti – was from the excellent debut album, A Certain Trigger by Maximo Park. One of the bands I always wished to see live but that would probably do little for my tinnitus…
Fixed stuff here for newcomers
There is lots of news every week from the cooling industry and plenty of newsletters that cover it well. The intention is to keep this newsletter focused on the most prominent f-gases (fluorinated greenhouse gases), the most common of which are refrigerants and importantly their environmental impact. That’s the lane I’ve chosen - I’ll do my best to stick to it.
The What
Below is the seven (formal) greenhouse gases that countries and companies should track, report and hopefully reduce.
Carbon Dioxide (CO2)
Methane (CH4)
Nitrous Oxide (N2O)
Hydrofluorocarbons (HFCs)
Perfluorocarbons (PFCs)
Sulphur Hexafluoride (SF6)
Nitrogen trifluoride (NF3)
Not to mention the still circulating, ozone damaging chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and the ‘new-generation’ hydrofluoroolefins (HFOs).
Hopefully you can spot the pattern.
The Why
Emissions from f-gases and refrigerants have been the fastest growing greenhouse gases over the past decade (more than CO2 and methane - check out IPCC WG3 summary for policy makers). They are also classed as super pollutants given their outsized global warming and other environmental impacts.
You can find my basic primer here and a plenty more detail in the whitepaper here
Some useful permalinks
The scale of the climate challenge can often feel daunting. This piece helps me take a step back and understand where we need to focus first - recommend a read.
There are plenty of technology solutions available to address the cooling and refrigerant challenge. You can find many of them here
Beware when the same entities who have contributed to the current f-gas problem propose you new solutions… This is a good place to get up to speed.