See all forum discussions about CS-v4 EAp2
 Subscribe to new posts about CS-v4 EAp2 Post a new question aboutCS-v4 EAp2
See LEEDuser’s guidance on CS-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?

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

CS-v4 EAp2:Minimum energy performance

VAV Fan-Powered Box Minimum Stop

Hi,

I am working on an energy model for core and shell office building. To reduce the reheat energy the mechanical designer planning to reduce the minimum stop for fan-powered boxes. If we showed in the “Minimum IAQ Performance Calculator” that the fan-powered box minimum stop is 20% of peak primary airflow, should we model that percentage in the proposed and baseline models? or only in the proposed model and keep the baseline model at 30% as required by G3.1.3.14?

Thank you,

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  »

Fri, 12/20/2019 - 16:09

Only the Proposed case would get modeled with the reduced minimum stop. The Baseline should always be modeled with a minimum of 30%.

Fri, 12/20/2019 - 16:28

Thanks Tyler, what about the outside air flow rates should they be still modeled the same in both proposed and baseline according to G3.1.2.6 ? or a different calculation should be done for the baseline because the minimum stop plays a role in determining the outside air flow rate? 

Fri, 12/20/2019 - 16:48

Beginning in ASHRAE 90.1-2010 the outside air flow rates are more typically not modeled the same because of exception c to G3.1.2.6, since most designs include varying degrees of over-ventilation relative to the code minimum. However, the "amount required by the rating authority or building official" would be the code minimum as calculated for the Proposed design. Therefore, a separate calculation of the Baseline code minimum outside air would not be required. 

Fri, 12/20/2019 - 17:02

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.