Innovations in Ventilation: Wind cowls in the 19th century

At the beginning of the 19th century, health,hygiene and the wellbeing of dwellers became important. Adequate ventilation was recognized as a key element in a hygienic environment. To ensure sufficient air change rate in large buildings, two main artificial ventilation methods were developed: mechanical ventilation systems, which include fans and ventilators, and heat- and windinduced low-pressure ventilation systems or forced ventilation by heating and wind (van der Tempel et al. 2011).
Heat- and wind-induced low-pressure systems In heat- and wind-induced low-pressure systems, the temperature difference between outdoor and indoor temperature was increased, thus creating low-pressure differences to induce an air flow in the building to extract the foul air. In winter, the natural temperature difference between interior and exterior air was sufficient to supply fresh air and to extract the used air from the rooms, but this was not the case in summer. Heating elements were introduced into the duct system to induce an adequate draught in the air channels. Although the temperature difference was the main source of air displacement, the flow was also influenced by wind. An air extraction element on the roof of the building was added to the ventilation system (Cloquet 1898, 3). The wind cap or cowl prevented rain from entering the chimneys,but also inhibited counter flow and amplified the draught by maximizing wind effect. As a separate smoke channel was included in chimneys,
the cowl also prevented the re-entry of smoke into the air channels. In this paper, we shall focus on
these wind caps and cowls.

ISBN:978-2-7084-0929-3

Jaar van publicatie:2012

Trefwoorden:wind cowl, ventilation, nineteenth century, patent research, construction history