05 50 00 Metal Fabrications 05 59 00 Metal Specialties 08 13 00 Metal Doors 23 31 00 HVAC Ducts and Casings 23 33 00 Air Duct Accessories 45 39 00 Fabricated Metal Product Manufacturing Equipment 50 61 00 Construction Material Supplier 50 64 00 HVAC Supplies

23 00 00 Heating, Ventilating and Air Conditioning (HVAC) 23 01 00 Operation and Maintenance of HVAC Systems 23 31 00 HVAC Ducts and Casings 23 33 00 Air Duct Accessories 50 59 00 Construction Material Delivery/Hauling 50 61 00 Construction Material Supplier 50 63 00 Equipment/Tool Sales 50 64 00 HVAC Supplies

23 00 00 Heating, Ventilating and Air Conditioning (HVAC) 23 07 00 HVAC Insulation 23 31 00 HVAC Ducts and Casings 23 32 00 Air Plenums and Chases 23 33 00 Air Duct Accessories 23 35 00 Special Exhaust Systems 23 38 00 Ventilation Hoods