Feel the Pain

I waited until it really hurt - the lesson for refrigeration

It is not often that I get thirty minutes to myself, where I’m physically restrained, and can do little other than think.

And so, it was this week, as I lay inside the MRI scanning machine at the local medical centre. Surrounded by a cacophony of staccato beeps, hums, and electronic chattering interrupted by the odd shudder. Being swallowed-up by that big magnetic doughnut gave me the sense of being inside a living being.

Nothing too serious to report though. I have pain in my right knee which I thought was a cycling injury but turns out to be a benign tumour. One that will likely need removing at some point (and I doubt chatGPT would furnish you with that type of unnecessary detail).

But it got me thinking.

I had overlooked my symptoms for some time, and only acted when the pain got serious. There is a strong parallel here with refrigerant and cooling systems. And as with my knee, you often need to look well below the surface to really know what is going on.

The Internal Method

Photo by Owen Beard - Not an MRI imagine of my knee…

The concept of the ‘internal method’ was first explained to me by the industry veteran, Klas Berglöf. He has been banging the drum about pro-active data monitoring of refrigeration and heat-pump systems for many years. Probably to the point where he is now a little tired of repeating the same message, which so often seems to fall on deaf ears.

The internal method is a way of analysing refrigerant-based systems using sensors and data, such as used by ClimaCheck. It goes beyond taking a few external measurements which is commonplace in the industry. It goes much deeper.

For those interested you can read about the method, and the SEI (system efficiency index) in depth here. If I had to do a laypersons summary in a couple of lines. It provides the ability to know how efficiently a system is running in the field, by comparing to its absolute theorectical best, given the conditions at the time.

For outsiders you might think this would be common sense best-practice. It rarely is.

The industry has long used metrics like COP, SEER or kW/RT to describe the operating efficiency of equipment. They are often used as an indicator for performance drop offs. They are useful to a point, but they are limited, providing surface-level insight given they are based on predefined conditions. They are like the X-ray I had before my MRI. There was some useful information, but it didn’t reveal the underlying cause of the problem. It was the MRI, not the X-ray, that exposed the tumour.

The internal method for refrigeration systems can be considered in the same way. It provides insight on the inner workings of the sub-systems within the refrigerant cycle. When internal data (pressures, temps and power) is collected over an extended period, and coupled with some analytics, it can reveal an enormous amount.

It can spot an array of anomalies, pending failures and flag refrigerant leaks. It is a deep dive, medical examination for refrigeration and cooling systems. The 24/7, 365 MRI.

Numerous reports and case-studies have repeatedly shown how much energy, refrigerant emissions, repairs and loss of product could be saved with such monitoring systems. Especially those using the internal method. But still it is a tough sell.

Perhaps because the operators themselves don’t feel any pain directly. It is not throbbing away inside their knee urging them to act. In my experience, energy price rises rarely motivate action. Failures sometimes do. But often when there is a failure, there is a scramble to fix, and little effort to avoid repeats. People forget and move on.

My interest in refrigerants is because it addresses emissions from energy and the refrigerants themselves. Keeping a system healthy, means less of both. This is before you even start talking cost savings, avoided product loss, risk mitigation or improved safety.

You could also say my mission is to help operators recognise and act on the dull ache, before it becomes full-blown pain.

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…

You knew this was coming… Yes, you can find f-gases in MRI systems.

Having done some energy assessment work inside hospitals previously, I had come across the use of chilled water for cooling CT scanning equipment. I hadn’t managed to see under the covers of MRI systems before.

To create their intricate images, MRI scanners use a large magnet, which operates by way of a sizeable electrical current, which in turn produces significant amounts of heat. This heat is normally removed through a liquid helium bath, and some designs use an external chiller to provide additional cooling for the process.

A quick search through the product datasheets of MRI chiller suppliers, reveals they use HFC refrigerants (examples such as r134a and r407c) with some now moving to the newer HFO refrigerants. Which also happen to be fluorinated (i.e. f-gases), and problematic despite their ‘low-GWP’ tags. I’ll be doing a deeper dive on these in upcoming additions, but this is a good place to start.

As a side point, it also seems that helium supplies are under pressure, and there is increased emphasis on system maintenance, to avoid losing it. There are companies cropping up to provide real-time data monitoring of MRI systems, much like I described above. An MRI for the MRI…

You can probably gather they also use a bit of energy. By some studies, in the region of $25,000 USD per year. My own short scan not insignificant, and no doubt included in my bill.

Right, that’s all for this week and ‘till next time

Adrian.

p.s. the title from last week’s edition – Back Together - was from my Soulfuric in the House record circa 2005. Suitable for when trying to knock out a newsletter…

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)

There is also 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.