Natural smoke and heat exhaust ventilation (NSHEV)
Pneumatic CO₂ or electric 24 V drive for opening domes with natural smoke and heat exhaust. We coordinate the design, control and necessary equipment with the requirements of your facility.
For new construction, renovation or checking of an existing system.
Example of an open dome from the NODT II program.
Two types of drivePneumatic CO₂ and electric 24 V.
Selection according to the projectDome, upstand, drive and control as a coordinated set.
Post-installation supportInspections, maintenance and service of mechanisms.
NODT II presented program
Pneumatic or electric drive?
Both open the dome for natural smoke extraction. The activation method, control and daily ventilation are coordinated for each individual implementation.
Pneumatic opening
CO₂ drive
The opening mechanism uses propellant gas from a cylinder. For the pneumatic opening itself, no electricity is required; the actuation method and other connections are part of the system selection.
Presented versionNODT II with an opening angle of 140°.
ActivationVarious valve versions, thermal activation also in the brochure.
Daily ventilationOption of an additional motor or pneumatic cylinder for ventilation.
An electric actuator opens the dome. The control unit, power supply and smoke ventilation activation must be coordinated with the project requirements.
Presented versionNODT II with an opening angle of 140°.
OperationElectrical opening and closing via appropriate control.
Daily ventilationPossible with appropriate design and coordinated control method.
The drive has not yet been determined? Start with a description of the building and project requirements that you already know.
Information for the designer
Two actuator types, specified as part of the complete system.
Catalog classifications of the described NODT II systems
Feature of the described design
Pneumatic NODT II
Electric motor NODT II
Drive
CO₂, opening/closing valve
24 V
Catalog opening angle
140°
140°
Wind load
WL 1500
WL 1500
Snow load
SL 750
SL 750 or SL 500, depending on the design
Low temperature
T(0)
T(0)
Opening reliability
RE 50
RE 1000
Heat resistance
B300
B300
Fire response
E
E
On a smaller screen, scroll the table left or right for all data.
The classifications apply to documented configurations, not to every product with the same motor. Suitability for the building, required aerodynamic area Aa, dimensions, drive and upstand are confirmed by the design solution and documentation of the selected system.
Pneumatic opening with CO₂
The stored gas enables fire opening without electrical power to the drive itself. The triggering method is determined by the control and the appropriate thermal ampoule. Daily ventilation can be an additional function with a separate electric or pneumatic drive.
Electric opening
The 24-V drive is connected to the appropriate control unit, activation and power supply. The catalogue for the described system states opening in less than 60 seconds. The scope of power supply, feedback and ventilation control is part of the selected system solution.
Data according to the POS Plastika product range and the Rooflight domes and strips catalogue, edition 2026. The final dimensions, composition, equipment and associated documentation are confirmed in the offer.
Two different tasks
Smoke extraction and daily ventilation
NSHEV is intended for natural smoke and heat removal in the event of a fire. Daily ventilation ensures air exchange during normal use of the space.
The same opening can perform both tasks with the appropriate equipment, but a conventional ventilation opener does not in itself constitute an NSHEV device.
Electric drive ≠ mechanical exhaust
In the 24 V version, electricity moves the opening mechanism. Smoke exhaust through the open device is still natural. Mechanical exhaust uses fans.
In the enquiry, write whether you also need daily ventilation in addition to fire exhaust.
From request to offer
What we need to select a system
If you already have a design or fire safety study, roof plan or inventory, send the relevant part of the documentation.
01 / FACILITY
Project and purpose
Location, purpose of the facility, new construction or renovation and description of the need. Add known requirements for smoke exhaust, activation and daily ventilation.
02 / OPENINGS
Dimensions and existing condition
Number of openings, width and length with unit and information about what is being measured. When renovating, add the height and condition of the upstand, photos and the label of the existing device.
03 / SYSTEM
Drive and control
Planned or existing drive, control center and connections. If you do not have a choice yet, start with the project description and documentation that is already available.
The aerodynamic area Aa is not just the width × length of the opening. If the project specifies it, send the required value. The suitability is checked for the specific composition of the device, upstand and opening.
Details and placement
Examples of devices and mechanisms
Click to enlarge the photos. Equipment and design may vary depending on the ordered set.
Detail of the pneumatic opening mechanism.
Example of the opening mechanism; the photo does not specify the model or drive voltage.Example of placing the dome on the roof next to solar panels.
Installation and control
The upstand and clear opening are part of the specification.
Schematic installation of the NSHEV system on a standard conical upstand.Schematic installation of the NSHEV system on a KNICK upstand.
Changing the shape of the upstand changes the relationship between the construction, clear and nominal dimensions. The geometric area of the opening Ag and the aerodynamic area Aa are not the same. Therefore, the device is not selected only by the external dimensions of the dome.
Connection diagram of the rooflight, control unit, sensors and NSHEV control.
Technical basis
Brochure and selection documentation
We supplement the program overview with technical data of the specific device and the requirements of your project.
Declaration of performance, device classes, aerodynamic free area Aa and instructions for installation, use and maintenance. We check the properties for the agreed composition.
The brochure contains information about the presented program; it does not replace the documentation for the specific ordered implementation.
Link to the store
Order standard domes online; request a quote for a smoke ventilation system
You can inspect the standard domes in the store. The complete smoke ventilation assembly is specified separately.
The NSHEV drive is not listed in the descriptions of the standard domes below. Their price therefore does not represent the price of the system with fire opening and control.
For an overview of materials, dimensions and common opening methods, visit the skylight page.
Create an enquiry
Describe your project
The selected purpose and drive are transferred to the form. Add a description of the need and known information there; plans and photos can be sent by email.
We offer inspections and service for smoke and heat exhaust mechanisms, including checking the possibility of replacing components with suitable original parts.
Send the device designation, photo, location and description of the need. We will coordinate the scope of the inspection, availability of parts and the date for your system.
Prepare device data
The data from the plate, documentation of the existing system and the record of the last service are useful. For a new system, follow the operating instructions and the planned maintenance plan.
Smoke ventilation with Stelux and continuous rooflights.
Stelux glass skylight
The dedicated glass opening version combines daylight with the planned fire function. The drive configuration, opening angle and dimensions are determined according to the project requirements.
For larger roof areas, we can include dedicated opening parts or a double flap. Various drives and activation methods are provided for daytime ventilation and fire opening.
For service, prepare the system code, dimensions, drive type, fault description and available documentation. The scope and periodicity of inspections are determined according to the manufacturer's instructions, the requirements for the facility and the actually installed equipment.
FAQ
Before specifying a smoke ventilation system
From the opening method to data for offering and supporting existing devices.
What does NSHEV mean?
NSHEV stands for natural smoke and heat extraction. Smoke and hot gases are extracted through openings provided for this purpose. A rooflight dome can be part of such a system if the device, drive and other equipment are selected in accordance with the project.
Is a 24 V drive a mechanical smoke extraction?
No. In the described design, an electric motor opens the dome; the smoke is then extracted naturally. Mechanical smoke extraction uses fans. On this page we present devices for natural smoke and heat extraction.
Can I also use NSHEV for day ventilation?
With the appropriate design, yes. For the pneumatic system, the brochure provides additional equipment for day ventilation; with the 24 V design, use for ventilation is also possible. The required functions and control must be coordinated for the selected system.
Does a conventional dome from the store include NSHEV?
The NSHEV drive is not listed in the descriptions of the associated standard domes. Their prices therefore do not represent the price of the entire NSHEV system. For fire exhaust, please send project requirements so that we can coordinate the dome, upstand, drive and control.
What dimensions do you need for a quote?
Width and length with units and an indication of what you measured: construction opening, clear dimension or outer dimension of the upstand. When renovating, add a photo and information about the existing system. If the project specifies an aerodynamic area Aa, also state this requirement.
What documentation do we check before ordering?
For the selected device and assembly, we check the declaration of characteristics, technical data and instructions for installation, use and maintenance. We align the required classes, aerodynamic area, triggering and control with the project data. The brochure is an overview of the program, not a replacement for the documentation of the specific assembly.
Do you also service existing mechanisms?
The offer includes inspections, maintenance and service of smoke and heat exhaust mechanisms. To check the service options, send photos, device designation, location and description of the problem. We determine the scope of work and the appropriate parts for the specific system.
Next step
Send your project requirements
We help check the appropriate composition and prepare a quote for your facility.
