Dear all,

when following ACP EN 13779:2007 and EN 15251:2007 in CS.IEQp1 and CS.IEQc2 we do experience a very uncertain conditions given by this method in terms of IAQ – fresh air supply. Acc. to EN 15251:2007 App.G it is possible to set classes from low to high IAQ (Category IV to I) + It is also possible to follow different methods of calculation (B1.2: Based on person and building component OR B1.3 Per person or m2 floor area OR B1.4 Based on recommended CO2). The categiry we chosse and the method we choose is then significantly implying the overall requirement: amount of fresh air needed.

Is this really flexible for us/investor to freely set the targeted class and the method of calculation of IAQ or is it somehow more specified? I did not find any further specification what class and calculation method should be taken.

What is the implication on the credit IEQc2 of the classes I to IV + 30%? Also very flexible then...

So do we have to still need to compare ASHRAE 62.1 requirements and then to follow EN 13779:2007 for the rest of ventilation system design requirements?

Example that I found clear is from the system DGNB:
- In accordance with EN 15251, the ventilation rate for non-residential buildings must be designed based on two components: building and occupancy. The building component is related to VOC emissions from the materials and systems evaluated in Indicator 1, Indoor Air Quality – Volatile Organic Compounds (VOCs). The occupancy component takes into account natural emissions from users as well as CO2 pollution caused by breathing.
By choosing category II then is for 50 points, III for 25 points, IV for 0 points.

Please could somebody clarify this?

Many thanks,
Petr