air roof exhaust ventilation fan system of commercial building with hooded foil thermal insulation chimneys flues and ducts

air building capony chimney circulation cold commercial conditioner conditioning cool cooling duct engineering equipment exhaust exhaustion extraction fan flue foil heat hood hooded house housetop hvac industrial industry insulation metal metallic nobody outdoor pipe pipeline pollution roof roofing rooftop smoke stainless steel system thermal tile tiled tube vent ventilate ventilation warehouse