How should clearance around a commercial oven be determined?

Please verify the following points and require itemized written supplier responses:（commercial oven oven-clearance） Leave space for ventilation, door opening, operation and maintenance, with extra attention to ventilation and gas piping. Do not place ovens directly against cardboard, plastic, refrigerators or flammable surfaces. 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.