science

R-469A

R-469A is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand R-469A rather than just read about it. In short: R-469A is a refrigerant blend consisting of 35% carbon dioxide (R-744), 32.5% difluoromethane (R-32), and 32.5% pentafluoroethane (R-125). History This blend was developed by TU Dresden and Weiss Technik (a member of the Schunk Group of companies).

Key takeaways

R-469A belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect R-469A to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of R-469A from memory before moving on to harder problems.

Reference excerpt

R-469A is a refrigerant blend consisting of 35% carbon dioxide (R-744), 32.5% difluoromethane (R-32), and 32.5% pentafluoroethane (R-125).

History This blend was developed by TU Dresden and Weiss Technik (a member of the Schunk Group of companies). The impetus for the development thereof was the restriction in use of the refrigerant Fluoroform (R-23) by EU regulation 517/2014 on fluorinated greenhouse gases. At that time, R-23 was the refrigerant used most often to achieve temperatures as low as –70 °C. Since 2014, R-23 has only been allowed to be used in new refrigerating equipment and devices within the context of transitional regulations. This has led to a significant shortage of the quantity available and an enormous increase in price. The aim of the project was to develop a new refrigerant suitable for temperatures down to –70 °C that fulfilled the requirements of the EU regulation and was neither flammable nor toxic. In 2019, the blend was registered with ASHRAE for the assignment of an R-number, which was allocated in the same year.

Properties

R-469A is a chemically stable, transparent and odourless gas mixture. Since it is non-toxic and non-combustible, it has been placed in safety group A1. The global warming potential (GWP) ) of R-469A is 1357 and thus less than 10% of the value for R-23 (GWP 14800). Thanks to the low GWP value, it fulfils the requirements of EU regulation 517/2014 on refrigerants for new systems even without the certificate of exemption otherwise necessary. Systems using the refrigerant R-469A up to 3.6 kg filling quantity are exempt from the Leak test in accordance with EU regulation 517/2014.

Use R-469A is used in climate simulation test chambers for reaching temperatures as low as –70 °C. It is used as a substitute for R-23. The properties of R-469A with regards to cooling rate, thermal compensation, and air distribution are almost identical to those of R-23. This makes the test results of systems using the two refrigerants directly comparable.

Trade names WT69

Individual references

Worked examples

Example 1 — a first encounter with R-469A

Start with the simplest possible case. Write down what R-469A claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to R-469A before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about R-469A ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of R-469A

In research: R-469A appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses R-469A in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: R-469A is common in secondary-school and first-year university syllabi. It links to neighbouring topics Refrigerants, so understanding it makes those chapters shorter.
In everyday life: Look for R-469A outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study R-469A in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what R-469A means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain R-469A out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is R-469A in simple terms?

R-469A is a refrigerant blend consisting of 35% carbon dioxide (R-744), 32.5% difluoromethane (R-32), and 32.5% pentafluoroethane (R-125). History This blend was developed by TU Dresden and Weiss Technik (a member of the Schunk Group of companies).

Why does R-469A matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study R-469A?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on R-469A.