Anyone planning or installing a smoke and heat exhaust system (SHEV), or replacing a drive in one, will come across several sets of rules: the state building code, the product standard DIN EN 12101-2 and the design standard DIN 18232-2. This overview shows what each one covers and what it means for window actuators in practice.
In brief: The building code determines whether and where a smoke vent is required. DIN EN 12101-2 covers the smoke and heat exhaust ventilator (NSHEV) as a tested, CE-marked product – window, fittings and drive together. DIN 18232-2 covers the design, air inlets, installation and maintenance of the natural smoke exhaust system. Maintenance is generally carried out at least once a year by a specialist company.
Which standards and regulations apply to smoke ventilation?
| Regulation | What it covers | Relevance for window actuators |
|---|---|---|
| State building code (e.g. § 35 HBauO in Hamburg) | Whether and where a smoke vent is required, e.g. in the stairwell of an escape route; opening size and operating points | Specifies which area must open and from where |
| Special building regulations and fire safety concept | Requirements for halls, retail and assembly buildings and other special buildings | Determine whether a system to DIN 18232 must be planned |
| DIN EN 12101-2 | Product standard for natural smoke and heat exhaust ventilators (NSHEV): testing, classification, CE marking | The drive is part of the tested device |
| DIN 18232-2 | Design, requirements and installation of natural smoke exhaust systems, air inlets, signage, maintenance | Air inlets must open reliably; maintenance at least once a year |
| DIN EN 12101-10 | Power supplies for smoke and heat control systems | In a fire, the drives are powered by the SHEV control panel with emergency power (battery) |
DIN EN 12101-2: the NSHEV as a tested unit
Since 1 September 2006, natural smoke and heat exhaust ventilators must be tested to DIN EN 12101-2 and carry CE marking. The requirements apply to the device as a whole, not to individual components. An NRWG consists of a window or rooflight, fittings and drive. For project-specific designs without testing, suitability can be proven through an individual approval (Zustimmung im Einzelfall) from the state’s highest building authority.
In practice this means: a single window actuator is not an NSHEV. Only the tested combination with the window makes it a smoke exhaust ventilator. We explain the difference in detail in our guide SHEV vs. NSHEV.
Performance classes to DIN EN 12101-2
| Class | Meaning | Examples | What the actuator has to achieve |
|---|---|---|---|
| Re | Reliability: number of opening cycles into the fire safety position | Re 50, Re 1000 | Open reliably over the long term, even after many ventilation cycles |
| SL | Snow load at which the device still opens | SL 250, SL 500, SL 1000 (N/m²) | Enough force to push the sash open against snow |
| WL | Wind load the closed device withstands | WL 1500, WL 3000 (N/m²) | Keep the sash securely closed |
| T | Lowest ambient temperature at which the device still opens | T(00), T(-05), T(-15), T(-25) | Operate even in frost |
| B | Heat resistance: device opens and stays open | B300, B600 | Open and stay open under fire heat |
The required classes are stated in the fire safety concept or the tender. The classes of the device are listed in the NSHEV manufacturer’s declaration of performance.
DIN 18232-2: design, air inlets and installation
DIN 18232-2 specifies how large the smoke exhaust areas must be and how the system is installed. The decisive figure is the aerodynamic free area (Aw), not just the geometric opening. Key points in practice:
- Air inlets: Without sufficient incoming air, smoke cannot escape. Air inlets must be adequately sized and open reliably in a fire – often via window actuators in the façade.
- Marking: Air inlets are marked with the sign “RWA-Zuluftöffnung – Bitte freihalten” (smoke vent air inlet – keep clear), trigger points with “Rauchabzug” (smoke vent).
- Smoke sections: Large rooms are generally divided into sections of no more than 1,600 m² using smoke curtains.
- Wall openings: If smoke is exhausted through the external wall, wind-direction-dependent control is required.
Building code: smoke vent in the stairwell
For stairwells that form part of an escape route, the state building code applies. In Hamburg, § 35 (8) HBauO requires either openable windows with at least 0.50 m² free area on every above-ground floor, or an opening at the highest point with at least 1 m² free area. This opening must be operable from the ground floor and from the top landing. In building class 5, the opening at the highest point is mandatory in addition to the windows. Other German states have similar but not always identical rules. More in our guide Smoke vent in the stairwell.
Power supply and control
In a fire, the drives must open even during a power failure. This is ensured by an SHEV control panel with emergency power supply to DIN EN 12101-10, to which smoke detectors, manual call points and the 24 V drives are connected. Important: a ventilation control unit does not replace an SHEV control panel. Vent Systems supplies ventilation controls such as the VS-C24-7A, but no SHEV control panels.
Maintenance: how often and by whom?
According to DIN 18232-2, a natural smoke exhaust system is normally serviced once a year in line with the manufacturer’s instructions, and only by a specialist company qualified for the system. Original or approved parts must be used as spare parts. In addition, the trade association BHE recommends a monthly visual inspection by the operator. In special buildings, the state inspection regulations may also require inspections by experts. Details in our guide RWA maintenance and inspection obligations.
What does this mean for your window actuator?
- Ventilation only: For comfort ventilation without a fire safety function, you can choose the drive freely based on force, stroke and voltage.
- RWA: The drive must belong to the tested NSHEV or be approved for the specific project. Agree the selection with the specialist planner, window manufacturer or installer.
- Replacement in an existing system: Before replacing, check with the installer or an expert whether the new drive is approved. We provide all technical data for this.
- Planning and tendering: For our Chain drives and other drives we provide Tender texts .
Frequently asked questions
Does every smoke vent window need CE marking?
A natural smoke and heat exhaust ventilator to DIN EN 12101-2 carries the manufacturer’s CE marking. If there is no test, for example with a custom façade, project-specific proof such as an individual approval is required.
Can I replace the drive in a smoke vent system myself?
Work on a smoke vent system belongs in the hands of a specialist company. Because the drive is part of the tested device, it must be confirmed before replacement that the new drive fits the device and is approved.
Does DIN EN 12101-2 also apply to smoke vents in stairwells?
That depends on the state and the building. In Hamburg, stairwells without openable windows in building classes 4 and 5 require a natural smoke and heat exhaust ventilator with at least 1 m² at the highest point. If in doubt, clarify the requirements with the fire safety planner or the building authority.
How often must a SHEV system be maintained?
Generally at least once a year by a qualified specialist company, documented in an inspection report. In addition, the operator carries out regular visual checks.
Does Vent Systems supply SHEV control panels?
No. We supply window actuators in 24 V and 230 V, ventilation controls, sensors and accessories. The SHEV control panel comes from the system installer.
Planning a system or looking for a replacement drive? Send us the details via our Project enquiry or the Contact form. We advise on sizing and ship from our Hamburg warehouse.
Note: this overview does not replace professional planning. The applicable state building code, the fire safety concept and the current versions of the standards are decisive.