Questions on CONTAM modeling for a deep underground parking smoke-control study

[KH Lee]

Dear Dr. Dols and CONTAM team,

Thank you for your helpful reply to my previous questions. I really appreciate your guidance.

I am currently using CONTAM for a smoke-control study of a mechanical underground parking facility under EV fire scenarios, and I would like to ask a few additional modeling questions.

In my case, I am modeling a deep underground parking level (e.g., B7) that has no direct openings to the outdoors.

1. For a deep underground parking level with no direct outdoor opening, what is the recommended way in CONTAM to represent the outdoor boundary condition and the make-up air path?
2. In this situation, should the fire floor be connected only to actual supply/exhaust duct terminals and vertical shafts that eventually connect to ambient, or is it acceptable to use an equivalent ambient connection for unknown leakage or make-up air?
3. Is it physically reasonable to model exhaust-only operation without an explicit make-up air path, or should some form of replacement air path always be included in the network?
4. When measured leakage data are not available, what is the recommended way to assign leakage characteristics for elevator/lift gaps, doors, shaft interfaces, and similar internal connections?
5. Are there defensible default approaches for selecting leakage area or flow element parameters, and how should these be calibrated so that the model does not create unrealistic make-up air or pressure behavior?
6. For smoke-control studies in CONTAM, which outputs would you recommend as the primary performance indicators?
   Would it be more appropriate to rely on actual exhaust flow, actual supply flow, interzone mass flow, shaft mass flow, and pressure differences rather than nominal ACH alone?

If there are any sections of the CONTAM documentation, example projects, or published references that you would especially recommend for this type of underground case, I would be very grateful.

Best regards,
Kwonhaeng. Lee

[Dols, William Stuart (Fed)]

I am not sufficiently familiar with the design requirements to provide engineering guidance on smoke management system design for underground parking garages.

The following may be helpful:

• Faramarzi, Afshin, Jongki Lee, Brent Stephens, and Mohammad Heidarinejad. 2021. “Assessing Ventilation Control Strategies in Underground Parking Garages.” Building Simulation 14(3):701–20. doi:10.1007/s12273-020-0677-3.
• The Handbook of Smoke Control Engineering provides guidance on the use of CONTAM (and other simulation tools) for the design and analysis of smoke management systems.
• https://www.nist.gov/el/beed/nist-multizone-modeling/case-studies/case-6: Includes some simulations of underground garages, but not as they relate to smoke management.

 

This is not an exhaustive list; additional information may be available in the literature.

Often, designers do not publish their work, so such information tends to be limited.

 

- Stuart

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