narrower concept Lüftungs- und Klimatechnik Concept air flow Concept air hygiene Concept air pollution Concept carbon dioxide Concept climatology Concept cold Concept dust Concept environmental impact Concept environmental loading Concept environmental pollution Concept gas concentration Concept heat Concept heat loading Concept hydrogen Concept insolation Concept nitrogen Concept ozone Concept precipitation Concept regeneration Concept saturation degree Concept smog Concept solar heat Concept sulphur Concept sulphur dioxide Concept temperature Concept