37 Maintenance and repair of heating, cooling, and air conditioning systems and installations, especially for buildings and other non-automotive applications and their parts as well as components, either individually or as assemblies; heat exchangers, evaporators, condensers, controllers, operating equipment, absorbers, lines, electric drives, pumps, and fluid distributors, regulating devices, heat pumps, housings; components and assemblies for connecting heating, cooling, and air conditioning systems to systems of district heating supply, solar heat generation (solar heating), geothermal production and/or all units generating waste heat; training in the use and installation of heating, cooling, and air conditioning systems and installations, especially for buildings and other non-automotive applications and their parts as well as components, either individually or as assemblies; heat exchangers, evaporators, condensers, controllers, operating equipment, absorbers, lines, electric drives, pumps, and fluid distributors, regulating devices, heat pumps, housings; components and assemblies for connecting heating, cooling, and air conditioning systems to systems of district heating supply, solar heat generation (solar heating), geothermal production and/or all units generating waste heat