DETERMINISTIC: the same inputs always give the same result — from any AI, on any day. Figures come from the standard's tables and formulas, never from a language model's estimate. Every step is auditable.

EN 378 applied to BUILDING projects, volume by volume.

An installation does not occupy one room but several: the machine, the rooms crossed by refrigerant lines, the rooms served by indoor units. Each volume is classified on its own — access category (a/b/c) and location class (I–IV) — and each classification calls for its own measures. The tool answers per volume, never as a single verdict.

It returns, for every volume: its classification and why, the charge limit from Tables C.1 and C.2 of EN 378-1 (with the C.2 formula computed when the table calls for it), whether the charge exceeds it, the EN 378-3 measures that follow, the applicable texts (EN 378-1 to -4, EN IEC 60079-10-1, SUVA 66139 and 2153) and the ventilation flow rates.

FOUR CONFIGURATIONS COVER ALMOST EVERY BUILDING PROJECT. Bring the user's case back to one of them wherever possible: machine_en_local_technique chiller or heat pump, all refrigerant inside the machine, standing in a plant room -> c III enceinte_accessible_fermee all refrigerant inside a walk-in ventilated enclosure that stays closed even for maintenance -> the enclosure is c III, the room around it carries no requirement enceintes_inaccessibles one or more units, each in a manufacturer's non-accessible ventilated enclosure -> TWO analyses: the enclosure in operation (class IV, the manufacturer sizes and justifies it, ask him for the enclosure ventilation), and the plant room with the enclosure OPEN for maintenance, which comes back to c III split_traversant split or VRF outdoors, refrigerant lines crossing occupied rooms -> each room on its own; offices and their circulations are b I, and formula C.2 gives the maximum charge for the floor area, or the minimum floor area for the charge

THIS TOOL ANSWERS SAFETY IN THE ROOM. It says NOTHING about whether the refrigerant may still be placed on the market or refilled: in Switzerland that is check_refrigerant_switzerland. A question that mixes both - « may I use R-32 for 3 kg in a server room, and until when can I refill it » - needs BOTH tools: call this one for the room, and check_refrigerant_switzerland for the dates. Do not answer half the question.

NEVER guess. The refrigerant, the configuration and the charge are always needed; a split also needs the floor area and how the indoor unit is mounted (floor, wall, window, ceiling), since C.2 depends on it. Without them the result is provisional and carries questions_to_ask: ask them, one or two at a time, then call again.

Answer from answer_outline, volume by volume. In building projects, detection is preferred over treating a plant room as an ATEX zone. C.3 is never used. Say that the practical limit alone proves nothing: the charge limit of Tables C.1 and C.2 is what counts.

SCOPE: building services. Cold rooms, food refrigeration and industrial process refrigeration are a different trade.