Hi,

I have a question in regards to the interpretation of the ASHRAE 90.1 article 6.3.6 (obligation to install a 50% energy efficiency recovery system on the 100% fresh air system).

I work on a project where a laboratory (without hoods) requires a 100% fresh air system (25 000 cfm) to ventilate the organic waste contained in the air (animal autopsy laboratories). No cross contamination is acceptable for the purpose of the laboratory.

We are planning to install a run around coil to recovery the exhaust air energy but as I understand the ASHRAE 90.1 standard, this installation is an obligation and it is not considered as a "credit" in our intention to over perform the energy efficiency performance of the building for the LEED process.

Here is my comprehension of the article and please, help me to clarify my thought.

1. In respect to 6.3.6.1, 100% fresh air system needs 50% recovery effectiveness.
2. The laboratory has no hood, so the exception 6.3.7.2 is not valid for our project.
3. The system does not exhausting toxic, flammable, paint or corrosive fumes or dust, so the exception 6.3.6.1.c) is not valid for our project.
4. All the supply air is admitted by one single fan and the entire air is exhausted by a single fan, so the exception 6.3.6.1.h) is not valid for our project.
5. All others exceptions in regards climate and design conditions are not valid for our project.

Does someone have already work on a LEED project with this kind of situation with laboratories?

Does organic waste in the air could be considered as "toxic" and then meet the exception 6.3.6.1.c) ?

Instead of exhausting the air by one single fan we install two fans, does the exception 6.3.6.1.h) will be met?

Do you know any new technology for energy recovery without cross contamination with efficiency better than 50% ?

Thank you for your help.

Best regards.

Hugues Boivin, ing., M.Sc.