40100000 Heating and ventilation and air circulation
40101700 Cooling
40101711 Centrifugal liquid chiller
40101708 Fan coil unit
40101716 Cooling tower
40101709 Air handling unit
40101702 Cooling exchangers
40101703 Evaporative coolers
40101701 Air conditioners
40101600 Air circulation and parts and accessories
40101601 Blowers
40101602 Air circulators
40101604 Fans
40101605 Fan guards or accessories
40101500 Ventilation
40101502 Air exhausters
40101503 Vents
40101505 Air diffusers
40101506 Ventilation pipes
40101800 Heating equipment and parts and accessories
40101805 Furnaces
40101802 Heat exchangers
40101809 Circulation heaters
40101806 Heat pumps
40102000 Boilers
40102004 Natural gas powered boilers
40102003 Electric boilers