Waste heat recovery: a tailor-made approach, not a one-size-fits-all recipe

The key? A personalized analysis to identify all the points where heat is available — and above all, where its recovery makes technical and economic sense.

1 ️: Heat recovery is tailor-made. We don't recover heat “because it's good”. It is recovered where it is available, stable and usable. This requires:

✅ A complete thermal audit (not only on refrigeration units!).

✅ A mapping of needs (heating, DHW, processes...).

✅ A profitability analysis (investment cost vs. savings) .Example: In an agri-food factory, hot effluents, combustion fumes or compressors can offer much more interesting resources than cold units.

2 ️ A refrigeration unit is designed to produce cold — not heat Be careful not to reverse priorities:If a refrigeration unit does not emit much heat, it is often because it is efficient at producing cold.Its role is not to heat, but to cool. If you get your heat back, that's a bonus — but it's not your primary objective.

3 ️ Where to look for fatal heat? Here are the sources that are often underexploited: Combustion smoke (furnaces, boilers) .Hot water (washing, CIP, effluents) .Compressors and motors (low temperature heat) .Synergies between workshops (internal or external reuse). 💡 In some cases, recovery from oven fumes can cover up to 50% of a factory's hot water needs — with a rapid return on investment.

4 ️ When recovery does not make senseEven if heat is available, you sometimes have to know how to give it up:

❌ Source that is too unstable (e.g. intermittent production).

❌ Non-existent thermal need (e.g.: factory already overcapacity).

❌ Too high adaptation cost (e.g. major changes in processes) .Example: Recovering 10 kW to heat an administrative space may seem virtuous, but if the investment exceeds €50,000, profitability is illusory.

🔎 Your road map

1 ️ Identify all heat sources (full audit).

2 ️ Prioritize the most profitable deposits (temperature, stability, proximity).

3 ️ Integrate recovery into a global logic (energy efficiency, synergies).

💬 And you, where are you? Have you already mapped the heat sources in your factory? Are you looking for methods to assess the profitability of your projects? Or do you want concrete feedback? 👉 contact me to discuss it!  Pascal@reeniu.eco