Natural ventilation

Natural ventilation or free ventilation (rarely aeration or natural draft ventilation) describes the exchange of air in buildings, which occurs due to natural pressure differences between indoor and outdoor air.

DIN EN 15242: 2007-09 (now replaced by DIN EN 16798-7: 2017-11) defines the concept of free ventilation as follows:

"Ventilation in which the air flows into the building due to natural forces through leaks (infiltration) and openings (ventilation) and leaves it through leaks, openings, shaft extensions or roof exhaust air outlets, including ventilation shafts for air extraction."

- DIN EN 15242: 2007-09

drive

The physical drive of a fluid flow is a pressure differential. In the case of free ventilation, a pressure difference can be induced by wind or different gravity on the inner and outer air masses ( buoyancy , chimney effect ).

The pressure difference driving the thermally driven free ventilation is calculated from the difference in density to the ambient air resulting from the temperature difference and the available lift height h . ${\ displaystyle \ Delta \ rho}$

Areas of application

Before the development of machines for conveying air ( fans , compressors ), natural ventilation was the only way to specifically ventilate buildings and was already used in antiquity, for example with the Egyptian pyramids . Today, natural ventilation is specifically used technically and used in large industrial buildings, especially when large amounts of heat are generated, such as in the steel and glass industry and in the construction of so-called cooling towers ( cooling towers in power plant construction). In agriculture, too, there are many stable buildings that are ventilated in this way.

In ecological architecture, there are also increasing numbers of cultural buildings with gravity ventilation. This makes it possible to largely do without ventilation technology with an additional energy requirement. Well-known examples are the hall buildings of the Waldorf schools in Cologne and Düsseldorf as well as the sports hall of the Odenwald School in Heppenheim -Oberhambach or the Prime Tower in Zurich and the metalworking school of the city of Winterthur .

literature

Residential ventilation - free and fan-assisted, Beuth, by T.Hartmann, E. Heinz ISBN 978-3-410-25270-2

Ventilation rules for free ventilation, K. Fitzner, U. Finke, 1st edition. Dortmund: Federal Institute for Occupational Safety and Health, Dortmund / Berlin / Dresden, 2012, ISBN 978-3-88261-105-2 ( online )

FVLR guideline 10: Natural ventilation of large rooms, Technology Working Group of the FVLR, Detmold, 2014.

D. Etheridge, Natural Ventilation of Buildings: Theory, Measurement and Design, John Wiley & Sons, Ltd, Chichester, UK., 2011. doi: 10.1002 / 9781119951773 .

F. Allard, Natural ventilation in buildings: a design handbook, James & James, London, 1998

Achim Trogisch, Mario Reichel: Planning aids ventilation technology . 6th, revised and expanded edition. VDE, 2018, ISBN 978-3-8007-4277-6 ( VDE-Verlag ).

Web links

Individual evidence

^ Beuth Verlag
↑ Lothar Dietze: Free ventilation of industrial buildings . Verlag für Bauwesen, 1987, ISBN 978-3-345-00178-9 .
↑ Eckehard Fiedler: Natural ventilation of industrial buildings. In: BHKS-Almanach 2007. Bundesindustrieverband Heizungs-, Klima-, Sanitärtechnik eV -BHKS-, p. 2–7 , accessed on January 20, 2014 ( article (pdf)): “Are these pressure differences used to bring air into a building to bring the exhaust air out, then we speak of natural or free ventilation. "

[1] Beuth Verlag

[Dietze_1987-2] Lothar Dietze: Free ventilation of industrial buildings . Verlag für Bauwesen, 1987, ISBN 978-3-345-00178-9 .

[Fiedler_2007-3] Eckehard Fiedler: Natural ventilation of industrial buildings. In: BHKS-Almanach 2007. Bundesindustrieverband Heizungs-, Klima-, Sanitärtechnik eV -BHKS-, p. 2–7 , accessed on January 20, 2014 ( article (pdf)): “Are these pressure differences used to bring air into a building to bring the exhaust air out, then we speak of natural or free ventilation. "