God Theory of Refrigerants: design a refrigerant, test it on a real compressor
By DigiEntropy Engineering · 2026-04-04 · 9 min read
A live blend lab for the classroom: mix your own refrigerant from pure molecules, get real CoolProp mixture thermodynamics, and predict how a real catalogue compressor would run on a fluid that doesn't exist yet.
About this post — Authored by an AI assistant using DigiEntropy's polynomial corpus, the universal compressor predictor, and the project's chart-generation tooling. Charts are produced by Python scripts that read the same database the live site queries; tables and formulas are pulled from the same engineering modules. Findings reflect the project's current dataset and methodology — send corrections or deeper questions to admin@digientropy.com. Last winter we made a strange claim on this blog: every compressor in every manufacturer's catalogue is really just about ten physical numbers, and one universal model reproduces thousands of vendor performance polynomials from them. We called it the God Theory of Compressors. This post is the other half of the story. Every refrigerant is about five numbers — molar mass, critical temperature, critical pressure, the acentric factor, and the molecular heat capacity — and corresponding-states physics builds almost everything else on top of them. We built an interactive lab to show that, and to let a student do something no manufacturer's software will: invent a refrigerant that has never existed, get real thermodynamics for it, and then run a real catalogue compressor on it. It is a teaching surface first. Where a textbook shows the ideal cycle for one fixed refrigerant, this lets a class turn refrigerant choice into a design variable and watch the physics respond. Every refrigerant is five numbers Reduce any pure fluid by its own critical point — pressure as $p/pc$, temperature as $T/Tc$ — and its saturation curve, its latent heat, its efficiency ceiling all fall onto near-universal shapes. The chemistry only decides where on the map a fluid sits; the map itself is shared physics. That is the corresponding-states principle, and it is the backbone of the whole lab. The four laws on that landing page are the syllabus in miniature: corresponding states (Law 1), the reduced latent-heat budget every fluid shares (Law 2), the ceiling that sets how much of Carnot any refrigerant can reach (Law 3), and the trilemma that says you cannot maximise capacity, efficiency and environmental safety at once (Law 4). The rest of the lab is those four laws made touchable. Blend your own refrigerant The centrepiece is the Blend Lab. Pick two to five pure molecules, drag the mass-fraction sliders, and the lab computes the mixture as a true multi-component Helmholtz-energy (HEOS) fluid in CoolProp — the same formulation the reference tool REFPROP uses — not a look-up or a proxy. Every property updates live. Here is R454B, the R32/R1234yf…