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Em-Vents are CE marked and fully certified to BS EN12101-2 and to Building Regulations ADB and ADL.  These electrically operated smoke vent rooflights designed to reduce smoke and heat buildup in buildings in the event of fire.

They are fitted with an integrated opening vent actuator.  Em-Vent smoke vent skylights allow key fire escape routes such as stairwells and corridors to remain usable with minimal smoke build-up.  Combined with Em-Dome skylights, they also help maximise natural light.

Available with either glazed or solid covers, Em-Vent smoke ventilators come in a wide range of shapes and sizes appropriate for various site requirements and to meet building regulation requirements of 1.0m2 or 1.5m2 free vent area.  These flat roof smoke ventilators open to 160° which exceeds the requirements of the new Smoke Vent Standard BS EN12101-2.

Em-Vents can also be used to provide comfort ventilation and as electrically operated access hatches.

Em-Vent accessories include control panels, additional smoke detectors and manual control points.

  • Fully certified to EN12101-2
  • Opens to 160° within 60 seconds
  • Choice of polycarbonate glazing or solid insulated cover available
  • Optional Wind Deflector to increase aerodynamic value (Cᵥ)
  • Choice of upstand types and heights available
  • Em-Vent Smoke Control Panel and accessories provide fully compliant control

Em-Vent Smoke Ventilators are supplied with patented high security screwbolts as standard.

Shapes & Sizes

Size range

Em-Vent Smoke Ventilators are available in an unrivalled range of over 55 sizes in square, rectangular and circular shapes. Most of these are available from stock.


The Em-Vent can be supplied with polycarbonate glazing or an insulated solid cover. The glazing element can be chosen from the wide range of options in the Em-Dome rooflight range such as single, double, triple or quad skin with a clear, opal diffused, bronze or HeatReflect finish in dome or pyramid profile. The key benefit of the polycarbonate glazing is that it allows natural light into the building. All polycarbonate glazing has an impact strength 250 times greater than glass and is AA fire rating to BS476 Part 3. Whitesales offer a 10 years warranty against discolouration and loss of impact strength.

The solid insulated cover can be provided as mill finish aluminium or polyester powder coated to any standard RAL colour.  It is available insulated with a 32mm panel or a 64mm thick panel providing exceptional thermal insulation values.

Thermal specification
Thermal transmission (W/m²K)*
Polycarbonate Single Skin 5.36
Polycarbonate Double Skin 2.68
Polycarbonate Triple Skin 1.78**
Polycarbonate Quad Skin 1.37
32mm Solid Insulated Cover 0.80
64mm Solid Insulated Cover 0.48

*Thermal transmission refers to U-Values.  For Ud-Values, please contact us.
**Measured in hot box in accordance with BS EN ISO 12567-2: 2005.


Em-Vents are constructed using high quality Em-Curbs to provide a thermally broken interface which helps improve the thermal efficiency of the roof.  Alternatively Em-Vents are also available as curb adaptors to suit existing or new builder’s upstand where these are of suitable dimension.

BS EN12101-2 stipulates that the Smoke Vent must be a minimum of 300mm above the finished roof level.  Where a 150mm Em-Curb upstand is supplied, this must be installed onto a builder’s upstand of at least 150mm high.

Em-Curb upstands are suitable for most roof finishes and available in the following options for this product:

  • Em-Curb ECO PVC 150mm Vertical
  • Em-Curb ECO PVC 300mm Splayed
  • Em-Curb GRP 300mm Splayed
  • Em-Curb ECO PVC 350mm Oversleeve Splayed
Em-Curb Upstands

All ventilation, access hatch and smoke vent options can be used in conjunction with Em-Curbs. Options available:

  • Em-Curb ECO PVC 150mm Vertical
  • Em-Curb ECO PVC 150mm Splayed
  • Em-Curb GRP 150mm Splayed
  • Em-Curb ECO PVC 300mm Splayed
  • Em-Curb GRP 300mm Splayed
  • Em-Curb ECO PVC 350mm Oversleeve Splayed

Em-Domes can also be installed to a builder’s upstand.

Thermal Transmission
Em-Curb Type U-Value (W/m2K)
Em-Curb PVC ECO 150mm Splayed 0.92
Em-Curb PVC ECO 150mm Vertical 1.00*
Em-Curb GRP 150mm Splayed 1.82
Em-Curb PVC ECO 300mm Splayed 1.00*
Em-Curb GRP 300mm Splayed 1.07
Em-Curb PVC ECO 350mm Oversleeve Splayed 0.89

*Measured in hot box in the vertical BS EN ISO 12567-2: 2005

Em-Curb Adaptors

An Em-Curb Adaptor is a thermally broken PVC adaptor for situations where a manual or electric opening rooflight is required and is installed to an existing builder’s upstand or an Em-Curb. Options available:

  • Em-Curb PVC Adaptor 50mm high
  • Em-Curb PVC Adaptor 80mm  high

Em-Collars provide a thermally broken solution for replacing existing or installing new rooflights and would typically be installed to a builder’s upstand. Options available:

  • Em-Collar 150mm Splayed
  • Em-Collar 150mm Vertical
Multiple Em-Dome rooflights

For extra long applications, e.g. 3m to 6m, two or more Em-Domes can be installed together by means of linked T-Collar adaptors.

These are self-supporting up to a span of 1m. For spans over 1ma structural support will be required. Where necessary, linked T-Collar adaptors are supplied in individual sections for jointing on site, utilising a standing seam detail.

Em-Curb upstands can also be used in conjunction with multiple rooflights.
For roof openings longer than 6m, we would normally recommend a continuous barrel vault rooflight such as our Em-Vault or T-Vault ranges.


The Em-Vent opening system is an electric actuator with a unique geometric movement and opens and closes the smoke vent by means of a 24 volt electric actuator.  It is available as a 700-1000mm and 1000-1600mm unit and opens the Em-Vent to 160˚ within 60 seconds.

Technical Data
LM70100 LM100160
Voltage 24V DC 24V DC
Current (with load) Max. 2.5 amp Max. 4.0 amp
Opening angle 160˚ 160˚
Ambient operating temperature -15˚C – +70 ˚C -15˚C – +70 ˚C
Operating time < 60 seconds < 60 seconds
Protection degree Min. IP54 Min. IP54
Product life comfort cycles 10,000 10,000
Weight 23kg 25kg
Size 700-1000mm 1000-1600mm

Please contact us for full technical data, specification sizes and aerodynamic values.


Em-Vent smoke control panels (EVSCP) provide natural Smoke & Heat Exhaust Ventilation (nSHEV) control for electrically operated systems.  Em-Vent smoke control panels are independently tested and fully certified to BS EN12101-10.

Many accessories are available as part of the Em-Vent package:

  • Fireman’s Priority Switch (EVSFPS)
  • Manual Control Point (EVSMCP)
  • Smoke Detector (EVSSD)
  • Heat Detector (EVSHD)
  • Room Thermostat (EVSRT)
  • Comfort Switch (EVSCS)
  • Key Switch (EVSKS)
  • Wind Sensor (EVSWS)
  • Rain Sensor (EVSRS)

For more information on the use of each of these accessories, please see our Smoke & Access brochure, or contact us.

Combined with Whitesales’ smoke ventilation unit, these Em-Vent control panels are able to offer a complete solution for the operation and monitoring of your smoke vent requirements.

Whitesales also provide wiring schematics for all smoke control installations detailing core size, and quantity and control panel programming. Schematic wiring diagrams are a pictorial way of showing electrical circuit, and its simplified pictorial representation shows the components and power and signal connections between the devices. Find out more by watching our video below.


When installed in accordance with the manufacturer’s recommendations, Em-Vents are expected to exceed the life of the roof covering.  Em-Vents are guaranteed against the effects of defective design, materials or construction for ten years, with an electric component guaranteed for 24 months, subject to certain conditions. ‘Special Project’ guarantees are available.  For further details contact us.

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