The hard gates

• Same system type — single split only. Multi-split, VRF, packaged, portable and window/wall units are not offered as ordinary results.
• Same duct status — a non-ducted unit is only ever matched to a non-ducted unit.
• Same phase — single- and three-phase are not interchanged. If the register did not record the legacy phase, confidence is capped rather than guessed.
• Same cycle type — a reverse-cycle unit is never replaced by a cooling-only one.
• Cooling capacity within 10% of the legacy unit.
• Heating capacity within 15% for reverse-cycle units, where both figures are recorded.
• Same mounting — wall, cassette, under-ceiling, floor or floor/ceiling. Where the legacy registration did not record the indoor-unit style, BecSpec asks you before ranking rather than mixing mounting types.

Refrigerant

Legacy units in scope use R22 or R410A. Candidates use lower-GWP refrigerants (R32, R290, R454B). BecSpec reports that a candidate uses a lower-GWP refrigerant — a whole-unit fact. It does not advise on recharging or retrofitting your existing equipment, and a shared refrigerant is never treated as a compatibility claim.

Confidence

• Strong specification match — every gate proven, mounting and phase known and equal, capacities within tolerance, identity resolved.
• Specification match — verify noted details — passes every gate, but one field you can confirm was missing from the register (e.g. the original mounting or heating figure).
• Exploratory — too much missing evidence to treat as a normal candidate.