Ventilation Test Results

Extensive tests have been carried out by a range of bodies into the effectiveness of ventilation at controlling Environmental Tobacco Smoke (ETS). Many of these are hypothecated whereby a mathematical model is used to calculate what the level of contamination may be. These models can be easy to manipulate according to what the researcher wants to prove (either high, or low levels of ETS concentration).
In our view there is more practical value in measuring what actually happens in a way that can be checked by other researchers using the same methodology.

Most of the tests have been run in bars or restaurants and of course the number of people smoking in the outlet will vary according to the level of trade. The normal practice is to test for worst case, i.e. the busiest evenings, in the knowledge that normal levels of contamination will be far below these levels.

The Black Dog study from Canada demonstrates that by using high pressure areas (non-smoking areas where more air is supplied than can be mechanically extracted) and low pressure areas (smoking areas where less air is supplied than can be mechanically extracted) smoke drift from smoking areas to non-smoking areas can be completely avoided.

The Bakers Arms from England demonstrates how ventilation can reduce the contamination in a typical pub with no smoking restrictions. This case uses a fabric diffuser above the bar counter – this is a duct or tube made out of fabric with the air forced through the weave of the fabric which allows a high airflow to be produced but at low speed due to the high surface area. This simple technology delivered a reduction of 95% in the level of respirable particles to which barstaff were exposed and effectively eliminated any exposure to carbon monoxide.

A summary of a number of tests carried out by the University of Glamorgan shows that ventilation is highly effective at reducing concentrations of ETS.

In the Netherlands the Organisation for Applied Scientific Research, the major independent not-for-profit testing organisation, tested the ventilation in three outlets in Rotterdam and Amsterdam. These tests showed that displacement ventilation – moving the air in this case from ceiling to floor – could reduce the level of ETS contamination by 90-95%.