Apparatus and installations for heating, cooling, steam generating, drying and ventilating; installations and apparatus for conditioning and air conditioning; air heating and cooling systems and apparatus; water heating and cooling installations and apparatus; ventilation [air-conditioning] installations and apparatus; humidifiers; dehumidifiers; air filtering installations; air purifiers; ionization apparatus for the treatment of air or water; filters for air conditioning; heating apparatus, electric; heating frames; air reheaters; radiators [heating]; radiators, electric; central heating radiators; convectors [radiators]; solid, liquid or gaseous fuels heating apparatus; heat pumps; stoves [heating apparatus]; underfloor heating apparatus and installations; heating installations [water]; radiant heating apparatus.