11 Heating, ventilation, and air conditioning equipment, namely, air chillers, air handlers, air filters; duct components for air conditioners, namely, dampers, fans, duct liners, fan coils, blower coils, heating coils, duct heaters, filters, air flow control valves, duct exhausters; air terminal units, namely, fan-powered terminal units, single duct terminal units, dual duct terminal units, induction terminal units, bypass terminal units with integral silencers, variable air volume terminal units, low profile terminal units, constant volume fan powered terminal units, quiet exhaust terminal units, retrofit terminal units, fan terminals; noise attenuators, namely, silencers for air terminal units, duct liners, acoustic steel panels used in air ducts and duct work for noise attenuators; air distribution equipment, namely, grilles, registers, diffusers, nozzles, combination ceiling light air diffuser units, user programmed diffusers, variable air volume diffusers, ventilation exhausts and extractors, structural parts and fittings for the forgoing equipment; heating, ventilation, and air conditioning systems comprised of evaporative air coolers; underfloor air distribution equipment, namely, floor grilles, floor diffusers, underfloor air terminal units, structural parts and fittings for the forgoing equipment, and underfloor air distribution systems comprised of one or more elements of the forgoing equipment; air displacement ventilation equipment, namely, supply air outlets, return air outlets, fan powered variable air volume supply air terminal units, single duct exhaust air terminal units, structural parts and fittings for the forgoing equipment; air displacement ventilation systems comprised of one or more elements of the forgoing equipment; suspended ceiling elements, namely, suspension members, ceiling panels, integrated lighting fixtures, diffusers, parts and fittings therefore, and suspended ceiling systems comprised of one or more elements of the forgoing elements; radiant heating and cooling equipment, namely, radiant panels, chilled sails, chilled beams, radiant heaters, underfloor heating systems, structural parts and fittings therefor, and radiant heating and cooling systems comprised of one or more elements of the forgoing equipment