If the air-handling unit is marketed or intended to be used as a space heater for the comfort of human beings, it is an air heating product according to the regulation.
Disclaimer: Please note that the European Commission cannot provide a legally binding interpretation of the EU legislation, as this is the sole competence of the European Court of Justice. Any remarks from the European Commission services are without prejudice to the position the Commission might take should related cases arise in a procedure before the Court of Justice.