How our AI co-pilot sizes a cold room — real engines, not a chatbot's guess
By DigiEntropy Engineering · 2026-03-29 · 6 min read
Watch our AI co-pilot size a cold room and shortlist compressors from one plain-English request — and see why the numbers come from real engines, not a language model's guess.
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.
Ask a general-purpose AI chatbot to "size a cold room and pick a compressor" and it will answer with confident, plausible-looking numbers. The problem: it made them up. For engineering work, a plausible-but-wrong number is worse than no number — it looks right until it costs you a compressor.
Our AI co-pilot is built the other way around. It does not invent the figures. It calls the same engines the rest of the platform runs on, and shows you the result as interactive cards you can read and edit. This post walks through one real request — sizing a cold room, then shortlisting a compressor — to show exactly how that works, and where every number comes from.
3.782 kW - the cold-room load - from the platform's cold-room load model
The total is 3.782 kW, and it shows you the heat balance: transmission 1.468 kW (39%), infiltration 1.114 kW (29%), safety margin 0.631 kW (17%), internal 0.43 kW (11%), and product 0.138 kW (4%).
177 - Bitzer models scanned - indexed for R449A
It scans the 177 Bitzer models indexed for R449A, evaluates each one's capacity and power at −28/42 °C from its EN 12900 polynomial.
22 - cover the load with headroom - then ranked by COP
It keeps the 22 that cover the 3.782 kW load with sensible headroom, and ranks the survivors by COP.
1.69 - top COP, the 4VE-10Y - 6.6 kW, Inside the envelope
4VE-10Y: 6.6 kW capacity, 3.91 kW power, COP 1.69, Inside the envelope.
+7.1% - COP gain for R455A - a 4DES-7Y moving off R404A
For that 4DES-7Y on R404A (13.39 kW, COP 2.24 at −10/45 °C), it flags R404A as banned under F-Gas (GWP 3940) and puts R455A on top: −96% GWP, A2L, a −10.6% capacity change and a +7.1% COP gain at this point, and Inside the envelope.
The request
You type it in plain English:
Size a cold room: 6×4×3 m freezer at −18 °C, 30 °C ambient, 500 kg/day of beef in at −5 °C, on R449A. Then shortlist the 3 most efficient Bitzer compressors.
Step 1 — it makes a plan and gathers the inputs
The co-pilot does not answer straight away. It lays out a short plan, then turns your sentence into a form.
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