Smoke hatches: design features

Roof smoke hatches are an integral part of building ventilation, the main task of which is to remove combustion products and heat from enclosed spaces in the event of a fire. These devices effectively solve the following tasks:

• Reducing the smoke content of evacuation routes, contributing to the safe evacuation of people from buildings and structures for industrial, civil and administrative purposes.
• Creation of better visibility in the fire zone, contributing to the detection of the source of the fire and its early localization.
• Lowering the indoor temperature, ensuring the safety of property and significantly reducing the risk of damage to building structures.
• Minimizing the threat to human life caused by smoke, poisoning by combustion and thermal decomposition products, and hot gases.

[contents]

In addition, such devices, under normal conditions, can be used as an additional source of ventilation, reducing the cost of general and emergency ventilation. A variety of design solutions for these devices makes it possible to install smoke hatches on any type of roof.

Design features

To date, there are many types and modifications of smoke hatches, with a wide range of sizes and dome filling. These devices can be horizontal and vertical, as well as built into light strips. In addition, there is a modification of smoke hatches, allowing them to be used as an exit to the roof.

Today, modern industry offers the following hatch designs:

1. Horizontal single leaf with a straight base.
2. Single leaf with sloping base.
3. Horizontal double leaf with a straight base.
4. Bifold with sloping base.
5. Horizontal with a straight base for roofs made of sandwich panels or corrugated board.
6. Horizontal with surface-mounted base, for installation on existing plinths.
7. Horizontal with a round base.
8. Embedded in «light strips».
9. Horizontal shutters.
10. Vertical blinds.
11. Roof hatches.

The material used in the manufacture of hatches

The supporting structure of these devices is made of galvanized steel with a thickness of 2 to 5 mm. The structure of the built-in hatch frame is usually made of aluminum profile, 1.5-3.0 mm thick.

As filling of the opened doors of this device is used:

• Cellular or slab polycarbonate, with varying degrees of density, thermal conductivity and transparency.
• Acrylic domes of various shapes, colors and transparency.
• Sandwich panels consisting of two sheets of galvanized steel with an insulating material located between them, the standard thickness of which is 50 mm.

The translucent materials used in the infill make it possible to use these devices as roof windows, thanks to which the energy consumption of the building is significantly reduced.

Most manufacturers of smoke hatches offer as additional options:

• Anti-vandal gratings.
• Fall protection nets.
• A portable weather station installed on the hatch, with rain sensors paired with the hatch leaf control device.

Control devices

Smoke hatches need devices that allow them to open and close their doors. Sash control can be:

• Electric. Electric smoke hatches provide reliability and operability, regardless of the influence of external temperature indicators on the drive. The disadvantages of such control include its dependence on power supply.
• Pneumatic. Devices equipped with a pneumatic drive are reliable and do not depend on the power supply, but are affected by condensate that may appear in the cylinder of the piston mechanism.
• Combined. This type of drive has all the positive qualities of the dome operation control mechanisms that exist today. The negative aspects include the rather high cost of such a device.
• Manual. Manual control allows the opening of the dome at the user level.
• With the help of a «gas spring». This design of the drive is designed to facilitate the opening of the cover and hold it in the open position. Mainly used for roof hatches.

Electric, pneumatic and combined actuators can be operated automatically or by remote start. Also, starting can be done by controlling the drive from the fire alarm system.

When operating in automatic mode, a signal is sent from the smoke detection sensors to the actuator, which opens the dome.

When operating in remote (manual) mode, the actuators are activated using the fire alarm button.

The most demanded manufacturers of hatches for removing smoke from premises in the domestic market

The Veza company, with divisions in Nizhny Novgorod and Kirov, produces a wide range of hatches filled with high-quality polycarbonate. Veza smoke hatches are produced in accordance with SNiP 2.01.07–85. The company has the ability to produce devices with heated doors, preventing them from freezing when operating in conditions of high humidity and low temperatures. For areas with low temperature indicators, an insulated, opaque version of manhole covers is available. The manufacturer uses electrical control systems.

Keraplast LLC is a subsidiary of the Finnish concern KERAPLAST OY. It supplies the Russian market with high-quality smoke removal equipment that has been tested and certified by the Research Institute for Production of the Ministry of Internal Affairs of Russia (VNIIPO). The company offers single-leaf and double-leaf hatches with a blank cover and translucent laminated glass. For the northern regions, a hatch model has been specially developed, with a dome thickness of 100 mm. All products of Keraplast LLC can be equipped with internal heating elements.

The Salamander company produces anti-aircraft and deaf smoke hatches that meet the highest international standards. The company offers a full range of work on the design, manufacture and installation of equipment, as well as automatic opening systems for doors, based on the technical specifications of the customer. As a material, the company’s specialists use: for the body, PVC and aluminum profile; as filling — translucent and matte acrylic.

Advice.
The assembly and installation of smoke hatches, as well as automatic opening of the shutters, requires knowledge, correct calculation, and experience in this matter. That is why the installation and configuration of such equipment should be handled exclusively by professionals.