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Interpretations Request Input

Original Request

  • Request ID: 8513
  • Requested By: Mark Blissett
  • Requester E-Mail: markb@mtlfab.com
  • Code Version: 2021
  • Code: MECHANIC
  • Code Description:
  • Chapter:
  • Section: 607.3.1
  • Topic: Dynamic ceiling radiation dampers
  • Question: The Florida State Building Code and the Florida State Mechanical Code require dynamic ceiling radiation dampers. Is an HVAC air distribution system that incorporates a static ceiling radiation damper and a fire-stat "less than equivalent" to an HVAC air distribution system that incorporates a dynamic ceiling radiation damper and a fire-stat?
  • Comment: None
  • Attachment 1: Download

Existing Interpretations and/or Declaratory Statements Related to this request

Input Received:

Yes
607.3.1 requires the damper to be tested and listed for use in dynamic systems where air flow may continue to move.
Michael Grimm on 02/25/2021 at 4:19 PM
No.
2020 FMC, 607.3.1 deals with Damper testing. Ceiling radiation dampers shall comply with the requirements of UL 555C or shall be tested as part of a fire-resistance-rated floor/ceiling of roof/ceiling assembly in accordance with ASTM E119.
2020 FMC, 607.6.2.1 deals with Ceiling radiation dampers. Ceiling radiation dampers shall be installed in accordance with the details listed in the fire-resistance-rated assembly and the manufacturer’s installation instructions and the listing.
UL 555C applies to ceiling dampers and ceiling air diffusers intended for use in HVAC systems where the airflow is operational at the time of a fire. Static ceiling radiation dampers are installed only in systems that are not designed to operate during a fire.
Pedro Quintela on 02/25/2021 at 5:16 PM
This is not a true code interpretation as it is a design question. Saying that and researching, I agree with Pedro’s response. I would clarify it with the statement that the designer needs to determine actual intent of the radiant damper’s use. Each type, static or dynamic, is tested for that specific air flow use.
Linda Patrick on 03/01/2021 at 6:48 PM
This is not a true code interpretation as it is a design question. Saying that and researching, I agree with Pedro’s response. I would clarify it with the statement that the designer needs to determine actual intent of the radiant damper’s use. Each type, static or dynamic, is tested for that specific air flow use.
Linda Patrick on 03/01/2021 at 6:48 PM
I agree with Pete's analysis.
Joseph Belcher on 03/03/2021 at 6:57 PM

Answer:

They are different. 2020 FMC, 607.3.1 deals with Damper testing. Ceiling radiation dampers shall comply with the requirements of UL 555C or shall be tested as part of a fire-resistance-rated floor/ceiling of roof/ceiling assembly in accordance with ASTM E119. 2020 FMC, 607.6.2.1 deals with Ceiling radiation dampers. Ceiling radiation dampers shall be installed in accordance with the details listed in the fire-resistance-rated assembly and the manufacturer’s installation instructions and the listing. UL 555C applies to ceiling dampers and ceiling air diffusers intended for use in HVAC systems where the airflow is operational at the time of a fire. Static ceiling radiation dampers are installed only in systems that are not designed to operate during a fire. If the question asked is if a static ceiling radiation damper is" less than equivalent" to a dynamic one, the answer to that is "yes". If the system is designed so that air movement is not deactivated, then the dynamic ceiling radiation damper is required and the static one is not equivalent.
On 03/05/2021 at 2:08 PM

Commentary:

The designer needs to determine the actual intent of the radiant damper’s use. Each type, static or dynamic, is tested for that specific air flow use.

Comments on Draft:

I agree with the draft
Pedro Quintela on 03/05/2021 at 2:15 PM
Me too
Linda Patrick on 03/05/2021 at 2:24 PM
I think the question asked is if a static ceiling radiation damper is" less than equivalent" to a dynamic one. I think the answer to that is "yes". If the system is designed so that air movement is not deactivated, then the dynamic ceiling radiation damper is required and the static one is not equivalent.
Michael Grimm on 03/05/2021 at 4:15 PM
I agree with Michael Grimm. the answer should be yes with the reasoning the same.
Joseph Belcher on 03/05/2021 at 7:30 PM
Publish Draft Interpretation