How can a reliable cooking-fume-purifier manufacturer be judged?

Verify test reports, rated airflow, efficiency, resistance, project cases, cleaning access, spare-parts supply and after-sales response rather than comparing only the lowest price. Ask the manufacturer to provide a selection plan based on cooking style, burners, ducting and local standards. Checklist: Define capacity, accuracy, materials and operating environment before requesting quotes on a uniform basis. Request specification sheets, test reports, certificates, maintenance manuals and spare-part lists. During acceptance, verify appearance, dimensions, functions, safety protection and packaging, and keep test records. Do not compare unit price alone; include customization, freight, spare parts, after-sales support and downtime risk. Keep written records of inquiries, confirmations, FAT, acceptance and warranty commitments.