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GAL Ventilation Systems









•Large scale gravity roof ridge ventilators

•Operable ventilation louvers (extruded sections)

•Multi-Use roof ventilators (ventilation and fire extraction)

•Multi-Use roof ventilators (ventilation & daylighting)

GAL´s primary products are operable air inlet louvers made of extruded aluminum sections and high performance gravity roof ridge ventilators. GAL´s products are mainly characterized by the high efficiency, respectively the high coefficient of discharge (CD or CVO) and are mainly used in the ferrous and non-ferrous metals industries and large industrial projects.

aTmos´s primary products are natural louvered ventilators and natural flap ventilators, and most of the product range is DIN EN 12101 certified for use as fire and smoke ventilation. In contrast to GAL´s products, these units are considerably smaller and modularized with easy manufacturing, transportation and installation.

Besides the premium products, the core know-how of our group lies within the capabilities and long-time experience in dimensioning natural and fire ventilation systems for all kind of applications and for an extreme range of climatic conditions from -50 to +50°C ambient outside temperature as turn-key projects, including on-site installation and commissioning.

The Princeple of Ventilation

By natural ventilation, buildings with high internal heat loads can be ventilated without the use of electric fans which lead to high operating costs. Caused by the temperature difference and the resulting density difference of the inside and outside air, a thermal updraft comparable to a chimney is created. This leads to a lower pressure in the lower part of the building and a higher pressure in the upper part of the building compared to the outside. This pressure difference leads to a ventilating air flow through the building.

Awell designed natural ventilation system is essential for:

•Functionality of the technological process (performance of a cooling bed for example)

•Protection of electrical systems

•Providing a healthy environment for people (lower temperatures and lesser dust exposures)


The " Neutral Plane "











Know-how and tools for engineering and dimensioning of natural ventilation systems

In a large industrial building, ventilation openings are designed in the facade and on the roof ridge of the building. The size and position of the ventilation openings for the natural ventilation of the ventilation zone are ascertained on the basis of

• pressure balance

• air flow balance

• heat flow balance

by iteration.

For dimensioning natural ventilation systems, GAL uses in-house developed non-public computer models, which are based on a thermally coupled 1-dimensional zonal model.

For more complex issues, standard computational fluid dynamics (CFD) software is used in cooperation with ANSYS Germany and Ansys´s HPC cluster is used.

High performance gravitiy ridge ventilators

Gravity roof ridge ventilators with a coefficient of discharge CD between 0.52 and 0.78.













Available with air flow regulation or permanent ventilator   

Available with sound protection up to >30 dB









The principle of smoke and fire ventilation

The principle of fire ventilation is based on the same physical principles as natural ventilation. Caused by the temperature difference and the resulting density difference of the inside and outside air, a thermal updraft comparable to a chimney is created. The resulting air flow exhausts the hot fire plumes and the smoke through the roof and therefore saves lives and protects the customers investments. In case of fire the fire ventilators are automatically opened by a temperature sensor or also can be opened manually by an emergency switch, which allows the escape of hot gases and smoke, and will give ample time for all the inmates to escape before the roof collapses either in part or wholly in the event of fire. Awell designed fire ventilation system is essential for:

•Live savings in case of fire

•Protection of the machinery and facility

•Providing a healthy environment for people


Smoke and heat exhausted in industrial buildings

          Without fire ventilation                           With fire ventilation
















Natural ventilation and smoke and heat extraction goes hand in hand as GAL´s SHEVs can be used for both applications and can be used for many energy saving ways of ventilation systems:

•Purely natural ventilation

•Hybrid ventilation with mechanical air inlets and natural air outlets via GAL natural roof ventilators

•Hybrid ventilation with natural air inlets via GAL louvers and windows and mechanical air outlets via electric fans

•Ideally suited for large scale commercial buildings with a central naturally ventilated atrium

•Combination of natural ventilation, smoke and heat extraction and daylighting

GAL SHEVs ( natural smoke and heat exhaust ventilators )

SHEV test and classification The building product ‘SHEV’ is the result of standard DIN EN 12101 Part 2 which applies to the entire European Economic Area. The SHEV is a naturally active smoke and heat extraction device. It is used to extract smoke and hot gasses from a building in the event of fire.

 In accordance with DIN EN 12101 Part 2, SHEVs consists of

•a ventilator or louver system with the associated component parts (profiles, seals, fittings)

•the drive system with the associated component parts (drive, panels, fittings)

Using the SHEV

In accordance with DIN EN 12101 Part 2, a SHEV must always be used if a natural ‘smoke outlet’ is required by construction regulations. A ‘smoke outlet’ means a smoke removal system in the event of fire (heat smoke removal) as a result of which a stabile, low-smoke layer develops close to the ground which enables the safe use of emergency exits. GAL SHEVs can also be used for daily ventilation as a multi-use ventilator and ensures an economic natural climate control for green buildings.

Product Development R&D

GAL has strengthened its R&D effort in order to develop smaller scale roof ventilators by utilizing cost effective CFD analysis before building actual prototypes.

Large scale GAL ventilator (CD 0.60 to 0.78)                                                                Development of low profile ventilator (CD 0.25 to 0.45)














Development of low profile ventilator (CD 0.25 to 0.45)