See all forum discussions about CI-v4 EAp2
 Subscribe to new posts about CI-v4 EAp2 Post a new question aboutCI-v4 EAp2
See LEEDuser’s guidance on CI-v4 EAp2»
FAQs about EAp2 :

Do the required savings for this prerequisite (and credit) need to come only from building energy, or also process loads?

Our project doesn't have enough energy savings to earn the prerequisite. Can we get there by incorporating onsite renewables?

Does the base building information need to be included in the minimum energy performance calculator, or is it sufficient to just include the tenant space?

Are there any exceptions to the daylight control requirement of ASHRAE 90.1–2010?

Our proposed design has insulation R-values that are below those prescribed by ASHRAE 90.1-2010. Can we still meet the prerequisite?

View answers »

Forum discussion

CI-v4 EAp2:Minimum energy performance

Proposed Design Demand Control Ventilation

Hi all,

I have a doubt regarding a CI project. The building is served by Dedicated Outdoor Airflow Systems (DOAS) that serves several floors. Our project is regarding only one floor. As per ASHRAE 90.1 - 2010, section 6.4.3.9, DCV controls are only required for spaces with high occupancy density served by systems with 1400 l/s of outdoor airflow or more. We know that each DOAS that serve the building (and the project) have more than 1400 l/s, however, each DOAS provides around 1200 l/s to the floor under certification.

As such, must spaces that have a high occupancy density in our project (as per the 6.4.3.9 section) need to comply with DCV controls?

The doubts is: each system's total outdoor airflow is higher than 1400 l/s (as a total), but each DOAS provides less than that threshold to our project.

Thank you very much in advance!

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Thu, 05/23/2024 - 13:24

Yes, spaces meeting the size and density requirements of 6.4.3.9 would need to be designed with DCV controls, unless any of the exceptions to 6.4.3.9 apply, since the airflow defined by 6.4.3.9(c) is the system airflow, not the airflow to the project space only. 

Thu, 05/23/2024 - 14:02

Hi Tyler, thank you very much for your comment. Adding up to the question above, please consider that the central DOAS units are not interviened (not in the scope of the tenant), only the air distribution on the floor under certification. The DOAS are landlord's propriety, constant volume and do not have any frequency driver installed, how would that be possible? My doubt here would be: if the system does not have a VSD or a pressure sensor to maintain setpoint, under controlled CO2 values wouldn't the space's VAV dampers that close just revert the outdoor air to the other rooms? If there is no pressure sensor nor a DSV for it to act, perhaps in this case it doesn't make sense to have the VAV dampers there. Please let me know if I wasn't clear here.. Again, thank you very much in advance!

Thu, 05/23/2024 - 14:51

Your explanation was clear. However, I am unable to provide design guidance for how to achieve this requirement with the system that's been installed. This would need to be coordinated with the landlord and the project's design engineers. 

Fri, 05/24/2024 - 09:35

Hi Tyler, Your answer back there was good enough to at least confirm my suspicious that this is not an easy and quick answer. It makes total sense to apply the DCV control. I'll have to double my efforts here to try to figure out a solution to this one. Meanwhile, if someone else has experience in this situation, please do leave here your insight. Thank you!

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.