1. Facts keep their provenance

Each record stores brand, model number, equipment type, source class, dataset ID and source URL. Certification dates are preserved rather than treated as manufacture dates.

2. Wildcard records are not exact models

ENERGY STAR records can use * or similar placeholders. They remain searchable, but this site does not create indexable entity pages for them.

3. Matched systems stay matched

Heat-pump rows can contain an outdoor model and a matched indoor model. The database keeps that relationship visible instead of presenting a system rating as a universal outdoor-unit fact.

4. Serial decoding is conservative

Supported formats return a confidence label and explanation. Ambiguous strings return no automatic answer.

5. No safety-critical guessing

Filter size, compatible parts, refrigerant charge, wiring, gas pressure and repair instructions are not inferred from a partial model code.