UL PRODUCT CATEGORY

Ceiling Air Diffusers, BZZU


Guide Information for Fire-resistance Ratings

716716.3607.6.2607.6.2.1607.6.3

GENERAL

This category covers ceiling air diffusers investigated for use in fire-resistance designs as detailed in Fire-resistance Ratings - ANSI/UL 263 (BXUV). Ceiling air diffusers are designed for dispersing the flow of air through suspended membrane ceilings and are provided with factory-installed protection material which serves as a heat-transmission barrier under fire conditions.

Ceiling air diffusers are intended for use in lieu of hinged-door-type dampers in floor-ceiling and/or roof-ceiling designs that specify the use of a hinged-door-type damper over each duct outlet. A certified ceiling air diffuser may be substituted for the hinged-door-type damper specified in the design in accordance with the provisions of the certification of the ceiling air diffuser. A hinged-door-type damper must be a specified component of the floor-ceiling and/or roof-ceiling design for this certification method to apply. The individual certifications of the ceiling air diffuser specify (1) the model number of the diffuser, (2) the type of assembly (floor-ceiling and/or roof-ceiling) in which the diffuser may be used, (3) the hourly rating of the assembly in which the diffuser may be used, and (4) the conditions under which the diffuser may be substituted for the hinged-door-type damper (e.g., one ceiling air diffuser for each 12 in. or larger duct outlet protected with a hinged-door-type damper).

These diffusers may be open on top when used with a return-air plenum (when permitted in the certification information), or connected to air-supply or air-return ducts using certified Class 0 or Class 1 air ducts and connectors. When flexible air ducts and/or connectors are used, they should be supported by a minimum 1 in. wide hangers or saddles at intervals, as necessary, to ensure that the duct and/or connector will not contact the back of the ceiling.

PRODUCT MARKINGS

A separate label located adjacent to the Certification Mark identifies whether the ceiling air diffuser has been investigated for use in static or dynamic systems. The label for ceiling air diffusers for use in dynamic systems also includes the maximum air flow and closure pressure for which the diffuser has been investigated. A ceiling air diffuser labeled for use in dynamic systems is also suitable for use in static systems.

PRODUCT IDENTITY

The following product identity appears on the product:

    Ceiling Air Diffuser

RELATED PRODUCTS

For information on related products, see Fire-resistance Ratings - ANSI/UL 263 (BXUV).

ADDITIONAL INFORMATION

For additional information, see Fire-resistance Ratings (BXRH).

REQUIREMENTS

The basic standard used to investigate the physical performance of ceiling air diffusers in this category is ANSI/UL 555C, "Ceiling Dampers."

The basic standard used to investigate the fire-resistance performance of ceiling air diffusers in this category for use in floor-ceiling and/or roof-ceiling designs in lieu of duct outlets protected by hinged-door dampers shown in those designs is ANSI/UL 555C.

The basic standard used to investigate the fire-resistance performance of ceiling air diffusers in this category for use in floor-ceiling and/or roof-ceiling designs that do not indicate the use of hinged-door-type dampers in the design is ANSI/UL 263, "Fire Tests of Building Construction and Materials."

Fire performance measured by ANSI/UL 263 is based upon the assumption that air movement will be effectively stopped at the start of a fire. Ceiling air diffusers intended for use in HVAC systems where the airflow is operational at the time of a fire, such as in a smoke-control system, or from other situations in which the fan system is operational at the time of a fire, are investigated for dynamic closure. Ceiling air diffusers intended for use where the air movement is effectively stopped at the start of a fire are not required to be investigated for dynamic closure.

UL MARK

The Certification Mark of UL on the product or carton is the only method provided by UL to identify products manufactured under its Certification and Follow-Up Service. The Certification Mark for these products includes the UL symbol, the words "CERTIFIED" and "SAFETY," the geographic identifier(s), and a file number.

Additional Certification Markings

Products covered under this category are additionally marked with the following information:

AS TO FIRE RESISTANCE
DESIGN NO(S). ____
SEE UL ONLINE CERTIFICATIONS DIRECTORY

or

AS TO FIRE RESISTANCE
SEE UL ONLINE CERTIFICATIONS DIRECTORY

Alternate UL Mark

The Classification Mark of UL on the product or carton is the only method provided by UL to identify products manufactured under its Classification and Follow-Up Service. The Classification Mark for these products includes the UL symbol, the word "CLASSIFIED" above the UL symbol (as illustrated in the Introduction of this Directory), and the following additional information:

CEILING AIR DIFFUSER
FIRE RESISTANCE CLASSIFICATION
DESIGN NO(S). ____
SEE UL FIRE RESISTANCE DIRECTORY
No.

or

CEILING AIR DIFFUSER
FIRE RESISTANCE CLASSIFICATION
SEE UL FIRE RESISTANCE DIRECTORY
No.

* * * * * * * * * * * * * * * * * * * * * * * * *

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Air Diffusers
Last Updated on 2014-03-03
BZZU.GuideInfo BZZU Active 20140303 20140303

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