Smoke curtains: Sa, S200, DH and DHA

For Dutch projects an important distinction has to be made.

The Dutch Building Decree (Besluit bouwwerken leefomgeving, Bbl) sets requirements in various situations for the resistance to smoke passage between spaces. For new construction this is determined in accordance with NEN 6075, which uses the classes Ra and R200.

Sa and S200 are product classifications for smoke leakage. Ra and R200 relate to the resistance to smoke passage of the separation between spaces.

These concepts may therefore not be equated one to one without further assessment.

Where a Dutch project calls for Ra or R200, it must be assessed whether the demonstrated performance of the curtain and of the other parts of the separation together are suitable to meet the project requirement set.

For projects in Belgium and Luxembourg we assess the application on the basis of the national rules applying there, the project specifications and the European product and classification documentation.

Protektis also supplies certified DH and DHA smoke barriers. These have a different function from a smoke-resisting closure with, for example, an Sa classification. DH and DHA smoke barriers are used as smoke barriers within smoke and heat control systems.

The European normative framework for this is EN 12101-1 – Smoke and heat control systems – Part 1: Specification for smoke barriers. Such smoke barriers can be used, for example, for:

• bounding smoke reservoirs;
• managing and directing smoke flows;
• limiting unwanted smoke spread within large open spaces;
• use as part of a designed smoke and heat control system.

DH

A smoke barrier with a DH classification has been assessed for functioning at high temperatures following the standard time-temperature curve for the classified period. The classification is combined with a duration, for example DH 60 or DH 120.

DHA

DHA concerns a smoke barrier that, within this classification system, meets the applicable criteria for more than 120 minutes under exposure to the standard time-temperature curve.

Protektis has certified curtain solutions within this DH/DHA system. Which version suits a project is determined by the required function, classification, dimensions, configuration and the other design parameters of the smoke control system.

This distinction matters:

• Sa and S200 relate to limiting smoke leakage through a closing construction.
• DH and DHA relate to the temperature and time resistance of a smoke barrier used within a smoke and heat control system.

A DH or DHA classification therefore does not automatically mean the curtain is classified Sa or S200. Conversely, an Sa classification does not automatically make a curtain suitable as a DH or DHA smoke barrier.

Where several performances are required, each must be separately demonstrable.

Smoke resistance and fire resistance are different performances.

Where the same separation requires fire resistance in addition to smoke resistance, that performance must be demonstrable too. Depending on the project requirements, a classification of E, EW or EI may be called for.

An Sa, S200, DH or DHA classification may therefore not automatically be translated into an E, EW or EI fire resistance classification — or the other way round.

In assessing a smoke curtain we do not look only at the letters on a data sheet. The following aspects, among others, are relevant:

• the function of the curtain within the fire safety concept;
• the required classification;
• the accompanying test and classification documentation;
• the field of application of the demonstrated performance;
• the dimensions and configuration;
• the guides and connection details;
• the connection to the building structure;
• the control system and the method of activation.

The performance must relate to the curtain construction and configuration as it is actually applied.

Protektis supplies a range of solutions for limiting and controlling smoke, including curtain solutions with Sa performance and certified DH and DHA smoke barriers.

We think it matters that a stated classification does not just appear on a data sheet, but is demonstrably supported by the right technical documentation.

Do you have a specification, a fire safety report or a project specification calling for Ra, R200, Sa, S200, DH or DHA? Send it to Protektis together with the dimensions and the project situation. We will assess which curtain solution matches the required performance technically, and which documentation is available for it.