R290 or transcritical R744
At 40 m³ frozen, R290 calls for forced ventilation of the space. R744 (transcritical CO₂) carries no ATEX constraint but needs a dedicated refrigeration unit (high pressure, 110 bar). For an industrial client who wants zero ATEX maintenance and a quiet long-term life, R744 is usually the right choice. For an isolated site with a well-ventilated space, R290 remains relevant and is 20–30% cheaper to install.

