Ventilation and Air cleaning
There are two accepted techniques for making air quality improvements: ventilation and air cleaning or filtration. These should not be confused with air-conditioning or comfort cooling where the objective is to make the air temperature more comfortable, not to improve the air quality. The advantages and disadvantages of the two technologies are set out below.
Advantages and disadvantages of ventilation and air cleaning:
| Issues | Ventilation | Air cleaning |
| Effectiveness in dealing with ETS particles | Highly effective | Usually highly effective but depends on equipment and usage of the filter |
| Effectiveness in dealing with ETS gases | Highly effective | May be effective on some if it has an active carbon filter |
| Ease of installation | Usually requires building work, sometimes extensive | Very simple, usually ceiling mounted with just electrical power required |
| Set-up cost | Equipment is inexpensive but installation often costs as much as the equipment itself | Basic equipment inexpensive |
| Maintenance cost | Low, unitary fans require wiping down and ducts cleaning every two years | High, frequent filter changes required, especially for highly effective electrostatic units |
| Effectiveness with smoking restrictions | Directed airflows work well | Not very useful as mixes the air in the whole space |
| Noise | Usually low | Can be high |
| Draughts | Cold draughts can be a problem | Not cold but an issue in places with low ceilings |
| Reliability | Usually robust and keeps working | Will stop working if filters are not changed frequently |
| Appearance | Not very obvious, ducts and fan units can be painted over | Often large boxes, although some are recessed into the ceiling |
| Availability | Very widely through heating and ventilation contractors | Usually through specialist companies |
However the results can be very useful.
The following graph from BSRIA research shows how quickly contamination is reduced by air cleaning, by ventilation and by a combination of the two. This shows that in 25 minutes an air cleaner running at the specified rate reduces the contamination in a room to almost zero.
These techniques can be used in shared spaces or in specialist smoking rooms. Additionally there are an increasing number of smoking booths that can be used.
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