Orishaft systems

Name: Orishaft modular smoke control duct system
Brand: Orishaft

Developed by Kera Group, Orishaft is an innovative modular smoke control duct system designed to enhance fire safety in buildings by preventing the spread of smoke and combustion products between fire compartments.

The system provides controlled smoke extraction and can also be used for pressurisation in buildings equipped with gas fire suppression systems.

By limiting the transfer of smoke and toxic gases between protected areas, Orishaft helps maintain fire compartmentation and supports effective smoke control and fire safety strategies.

Product Characteristics

Reliable fire compartmentation

Helps maintain fire separation between building compartments by limiting the spread of smoke and combustion products.

Excellent airtightness and thermal insulation

Very low air leakage reduces the required smoke extract fan capacity, helping to lower equipment costs. With a thermal transmittance (U-value) of 0.44 W/m²K.

Modular design and easy installation

Factory-manufactured modular sections enable quick assembly on site, reduce installation time and costs, and improve work safety. Suitable for single- and multi-compartment applications.

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Technical specifications and construction

Orishaft is a modular control duct system manufactured from hot-dip galvanized steel sheet with a pre-coated white RR20 finish. Its construction incorporates 100 mm mineral wool insulation and factory-installed fire stops.

Key technical parameters:

Fire resistance classification: EI60 (Ve) S1000 multi;
Tested and CE marked in accordance with EN 12101-7. Tested by MPA Braunschweig, Germany;
Thermal transmittance (U-value): 0.44 W/m²K;
Very low air leakage;
Modular construction with factory-prepared sections;
Maximum internal cross-sectional dimensions: 1000x1250 mm.

Available dimensions

Available standard interior dimensions are shown in the table. Dimensions can be combined, e.g., 600 x 1200 mm. The maximum inside dimension of a smoke extraction duct according to EN 12101-7 is 1000 x 1250 mm. Smoke extraction ducts larger than this cannot be CE-marked within the European Union.

Width mm	Length mm
600	600
800	800
900	900
1000	1000
	1100
	1200
	1250

Suitable applications

Applicable for both fire insulated ventilation duct (EN 1366-1) and smoke control duct (EN 1366-8) for vertical installation;
Possibility to use with both natural heat and smoke exhaust vents (EN 12101-2) and smoke exhaust fans (EN 12101-3);
Can be used both for smoke and heat exhaust and for pressurising;
Possibility to use with other systems, such as pressure equalization systems and inerting extinguishing systems;
Typical applications are commercial buildings, shopping malls, hospitals, residental apartment buildings, etc.

Application 1 (Through one fire compartment)

The product is installed e.g., through attic;
This installation ensures that the fire does not spread to another fire compartment or to the roof. In this application, the product helps to extinguish fire and minimizes property losses;
Natural smoke and heat exhaust ventilator (NSHEV) is installed on top of the product. NSHEV can be transparent or non-transparent;
NSHEV does not need to be EI rated, if the EI interface does not need to be closed on the horizontal part (NSHEV lid);
Shaft rises sufficiently above the roof surface, or a fire stop is installed between the NSHEV and the duct;
Typical applications are e.g., stairwells, where EI interface is in the ceiling.

Application 2 (Multicompartment)

Product is installed in multi-storey public buildings, such as hospitals, shopping malls, etc;
This application prevents the fire from spreading to other fire compartments;
Powered smoke fan is installed on top of the product, e.g., SMHA Hatch / Fläkt Group Oy;
EI60 multicompartment smoke dampers are intalled in each floor;
Shaft rises sufficiently above the roof surface, or a fire stop is installed between the NSHEV and the duct;
Smoke dampers and smoke fan are installed according to manufacturer’s manual;
Shaft is supported in each floor. Max. spacing between floors is 5000 mm.

NOTE! This kind of application is always engineered by a fire consultant and is approved by authorities.

Smoke extraction and fire compartmentation

Orishaft creates a dedicated vertical smoke extraction route, allowing smoke and combustion products to be discharged safely outside the building.

In single-compartment applications, the system can operate with a natural smoke and heat exhaust ventilator installed at roof level.

In multi-compartment applications, smoke is extracted using a powered smoke extract fan, while EI60 smoke dampers installed at each floor help maintain fire compartmentation and prevent smoke from spreading between floors.

The system can also be used for pressurisation applications, including buildings equipped with gas fire suppression systems.