I am working on a CI project that is the fit out of two floors of an existing lab building. The only HVAC available to the fit out floors is 100% OA from the DOAS units and warm chilled water for chilled beams (which is the predominant system). There are a few spaces per floor that are not lab spaces, such as conference rooms and write up spaces, where the latent load is too dense to use the active chilled beams. The cooling for those spaces is being provided with 100% OA from the DOAS.
Can the baseline system for the non-lab spaces also be 100% OA since that is all that is available from the base building?
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
September 29, 2023 - 8:29 am
I'm assuming you're applying Addendum cn to 90.1-2010 which adds exception d to G3.1.2.6, allowing the Baseline lab systems to be modeled as 100% outdoor air.
In either case I don't think you can model the Baseline system for the non-lab spaces as 100% OA simply based on that condition being the only option in the Proposed building. Addendum cn specifically applies this exception to baseline systems serving only lab spaces.
Cory Duggin
Senior Energy WizardTLC Engineering Solutions
53 thumbs up
September 29, 2023 - 10:30 am
Ya, I am using Addendum cn. I got confirmation that the non-lab spaces have to still just be 62.1 minimum OA eventhough the base building infrastructure is only a 100% OA system. Thanks