Parking Ventilation ACP Europe

If the EN publications do not specifically address parking garages, then you should use the ASHRAE 62.1 rates.  There is an exception that if two or more walls are at least 50% open, there is no need for exhaust.

Dear Andrew,

If the parking garage is enclosed (the exception mentioned by you doesn't apply) but there is a CO demand ventilation provided can the required air exhaust be reduced? As Samuel mentioned, value of 3.7l/s/m2 is quite high for European standards.

Agata, I do not know of any demand control allowance for required exhaust rate reduction. In my opinion, an enclosed parking garage is the absolute worst place to implement this. CO is a much different gas than CO2. CO will kill people if it is not exhausted. I would not rely on sensors and controls. I would provide the code required exhaust 100% of the time.

Agata, I agree with Andrew regarding the safety aspect of an enclosed parking garage. It can be risky to look only at one ASHRAE Standard. They often work together. ASHRAE 62.1 requires 3.7 L/s/m2. ASHRAE 90.1-2010 section 6.4.3.4.5 requires that exhaust systems automatically detect contaminant levels and stage or modulate fans flow rates to 50% or less of design capacity as long as contaminant levels are maintained.

For Reference:

Although you will need to comply with European standards, the US code series International Mechanical Code allows reduction of the parking garage exhaust rate down from 0.75 cfm/sf (3.7l/s/m2) to 0.05 cfm/sf (about .25 l/s/m2) as long as the contaminant (CO2 and NOx) are maintained.

Dear Andrew,

We also have some problems to justify that the exhaust rate of a part of an exterior parking that is covered is above standards of 3.7 l/s·m2. In our case this part of the parking is one-side opened and only has place for 10 cars, so natural ventilation should be enough. However, because of the exception is only applied if two or more walls are at least 50% open (we have only one wall 100% opened) the credit was denied. The opening is larger than 40% of the perimeter of the parking area, but I think is not enough to being exempted. Is there any way to justify that is sufficiently ventilated with Europe standards? or a way to compute the exhaust rate?

Hi, I don't think you will have any luck in convincing them that you comply with ASHRAE requirements. You simply do not seem to comply. They do allow alternate compliance, but typically want it to be more strict than ASHRAE. Imagine that someone has a local inspector just sign off on everything, USGBC wouldn't accept that either. If you only have a single side open, and 3 closed, I think there should be some mechanical movement of air, or an analysis showing that the natural draft will remove all exhaust fumes from the space.

Hello, In my case it  does not have two or more walls that are at least 50% open. Would it work to demonstrate air quality through a simulation  to compply with the requirment if the parking area was design to be natural ventilated?