ASHRAE 90.1 states that the design minimum fresh air ventilation of the Baseline should be as ASHRAE 62.1 or as ‘per building official’ which ever is higher but less than the Proposed Design.

So in our case - then our Baseline should be as per the local code (DS/EN 1752), which is higher. ASHRAE 62.1 says to use ASHRAE 62.1 values or local code whichever is more stringent - but do we consider more stringent to mean more or less fresh air volume? Considering LEED gives a credit point for 30% increased ventilation, presumably more stringent means more fresh air volume.

The thing I’m confused about, is that I know LEED review teams compare the LEED IAQ minimum ventilation calculator air volumes against the FAHU schedules and also the ventilation volumes shown in the energy modelling report (for the Baseline and proposed Models).  However, the ventilation rates for people and floor area in the LEED IAQ Calculator is fixed to ASHRAE 62.1  and the only thing you can change is the occupancy rates. So is there a risk that we may encounter problems in the future if the Baseline model ventilation volumes are higher than what is shown in the IAQ ventilation Calculator/ASHRAE 62.1.

And do the proposed design minimum ventilation rates (DS/EN 1752) need to be increased by 30% to get the LEED IAQ increased ventilation credit, or do they just need to be 30% above ASHRAE 62.1 as shown in the calculator?

Kind regards, Lise