23 55 00 Fuel-Fired Heaters 23 83 00 Radiant Heat Systems 23 81 50 Terminal Heat Transfer Units 23 82 19 Fan Coils

23 00 00 Heating, Ventilating and Air Conditioning (HVAC) 23 55 00 Fuel-Fired Heaters 23 57 00 Heat Exchangers for HVAC 23 20 01 Pumps 23 21 16 Hydronic Specialties 09 29 05 Lead Lined Gypsum 23 50 11 Heat Generation 23 52 10 Boilers 23 81 50 Terminal Heat Transfer Units 23 22 00 Steam and Condensate Piping and Pumps