Hello everyone,

I am currently working on a project located in Germany. The ventilation strategy for the apartments will be carried out through continuous exhaust fans located in the bathrooms, allowing air to enter through a window trickle vent.

Based on (CEN) Standard EN 15251–2007, which states that " Ventilation system can also refer to natural ventilation systems making use of temperature differences and wind with facade grills in combination with mechanical exhaust (e.g. in corridors, toilets etc.)" I feel this needs to be consider as "natural ventialtion", since in ASHRAE 62.1 it is also mentioned that "Natural ventilation systems shall be designed in accordance with this section and shall include mechanical ventilation systems designed in accordance with Section 6.2 and/or Section 6.3." (Please condfirm )

If so, to comply with the air quality requirement, I believe the best approach would be to use Alternative Compliance Paths (ACPs). Based on that, I have some questions:

1. Do monitoring requirements apply to this path? (Even if the exhaust fan would be working on-continiously?) 2. Are there exhaust ventilation requirements for bathrooms and kitchens? If so, which standard do they adhere to? 3. Are there filter requirements?