A “complete cleaning” is being offered for the existing residential ventilation. So far, filters have been serviced, but there is little information about the air ducts. Do not decide solely based on the package name. First have it explained which condition will be examined, which parts of the system will be worked on and which boundaries will be documented.
The cleaning needs an assignment to the system
Zehnder describes on its service page the inspection and cleaning of the air distribution system in addition to the maintenance of the ventilation unit. The services offered distinguish, among other things, between air ducts, outlets, filters and accessible silencers. [SYSTEM] That documents the described manufacturer service, not a blanket necessity for cleaning or suitability for any other system.
Our editorial recommendation: Provide model, existing plans, known modifications and previous service reports. Ask whether the offer fits this specific installation. Proof of a filter change does not automatically describe the condition of all concealed ducts.
Clarify the reason and the investigation
Is it a matter of routine maintenance, a specific anomaly or a particular case of damage? Describe this reason without diagnosing a hygienic cause yourself. A visible deposit of dust at the outlet does not permit a comprehensive assessment of the entire system.
Have the specialist explain which inventory assessment they need to make the decision and which services derived from that they propose. The article does not name a cleaning interval that applies to all systems and does not make any blanket claim about doubled power consumption or health improvements.
Translate the offer into concrete areas
Request a clear description of the included duct areas, equipment components and outlets. What is accessible and which open prerequisite must first be clarified? If a part cannot be worked on, that should be recognisable before commissioning.
Also ask about the protection of the rooms used, necessary preparations and the planned result report. The household does not remove valves or grilles for this purpose and does not introduce brushes, chemicals or disinfectants into the system. The chosen specialist method must fit the actual installation.
Fictitious case: A clean grille does not answer every question
An owner expects the treatment of concealed extract ducts, but the initially offered package names only the unit and outlets. He has the difference explained before commissioning. He then compares the confirmed scope of services with the report on the sections actually reached and worked on.
The result is a reasoned service decision with an appropriate delimitation, not a general hygiene certificate and not a guarantee of trouble-free system operation.