Hand over the system with a description of the system, demonstration of how to operate the controls and how to change filters. Also provide information on where to get replacement filters and written and illustrated instructions on how to change the filters when the time comes 3 or 6 months later.
The primary maintenance requirement is changing filters. Some ventilation units maintain a constant air flow rate when filters get clogged, but in so doing the fans get noisier. Older or cheaper systems just supply less air. So regular filter changes are important. Write the date of install on the filter. Most control units have a filter-change indicator but this is based on number of days.
It is an advantage if occupants can periodically check the system: some systems are so quiet that occupants may not notice if the fans stop running. Over a few years dust builds up on extract valves. These can be removed and cleaned, being careful not to change airflow settings or mix valves between rooms. Terminals should be removed for redecoration, but must be labelled by room if more than one is removed.
Excerpt from “How to build a Passivhaus: Rules of thumb”, chapter by Alan Clarke, Passivhaus Trust, April 2015.