How should the purifier, hood and fan be matched?

The hood captures fumes, the purifier treats them and the fan provides airflow and static pressure; all three must be matched to the same airflow, resistance and duct conditions. Replacing only the purifier without checking the fan and ducting often fails to stop fume leakage. 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.