The distinction between residential or non-residential ventilation units is based on the maximum flow rate and, for certain flow rates on the declaration by the manufacturer, as indicated in Article 2 of the regulation.
The expression "control system" could refer to the "indoor climate control system" or the "motor control system". The first one is e.g. related, for RVUs, to the choice of the control factor, (Annex IV-1-n of Regulation (EU) 1253/2014), whereas the second one is related to the declared type of drive (Annex IV-1-e (for RVUs) or Annex V-1-d (for NRVUs) ).
Specific categories of drive are explicitly addressed by the Ecodesign Regulation 1253/2014: as an effect of the provisions laid down in annex II for RVUs and Annex III for NRVUs, ventilation units have to be equipped with a multi-speed drive or variable speed drive. In case it is opted for the variable speed drive (VSD), as from definition 4 of Annex I (of Regulation (EU) 2531/2014), the VSD can be a separate delivery.
Concerning the "indoor climate control systems", specifically for RVUs, several options are possible (e.g. "manual control", "demand control"). The "indoor climate control system" is not subject to (generic) ecodesign requirements, but it affects the results of the SEC (Specific Energy Consumption) calculation, via the CTRL factor. Therefore, if a ventilation unit is placed on the market without the "indoor climate control system" or the "motor control system", the manufacturer has to provide the information on which system has to be installed on the ventilation units (cf. Annex IV-1-n), so that it complies with the requirements when putting it into service. The manufacturer has to CE-mark the product showing he has complied with all his obligations. The installer is responsible for ensuring that the product is put into service in accordance with the information provided by the manufacturer pursuant to Annex IV or V.
Suppliers also need to supply an energy label when the placing the ventilation unit on the market, even if without indoor climate control system(s), in which case the calculation of the label class needs to take into account the information provided by the manufacturer pursuant to Annex IV-1-n of the Ecodesign 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.