Ventilation

Ventilation refers to the process where clean air is mechanically and intentionally introduced into a space and the stale air inside the space is removed. In addition to the intentional ventilation, air enters into the space naturally and inevitably by the ‘air infiltration’ process. This refers to the uncontrolled fresh air flow into a given space through the unintentional or adventitious cracks or gaps inside the building envelope. Ventilation is a very important engineering control that allows the industrial hygienist to improve or even maintain the air quality in the work environment. It can also be used for dehumidification or thermal comfort when introduction of air from outside will assist in achieving the required psychometric conditions (United States Department of Labor, n.d.). Thus ventilation forms a very basic requirement for construction of any buildings.

The best time to use ventilation is when the space or building is occupied so that to maintain the outside air ventilation levels. Ventilation should also be used when humidification is needed especially in hospitals. It should also be used in time when air circulation is needed in commercial buildings so that to allow for thermal conditioning. The ventilation process should not be used if the outside air has been contaminated which will assist in preventing its introduction into a space. Industrial ventilation is necessary when a need arises for controlling emissions, chemical hazards and even chemical hazards especially in those areas that have high densities of occupant. Ventilation should also be used in the course of doing various activities such as welding, heating and cutting in a space that is confined United States Department of Labor, n.d.). In such a scenario, since ventilation cannot be obtained without the blockage of means of accessing the space, the employees in such confined space should be issued with air line respirators according to the policy requirements.

There are various situations where ventilation may not be used  which includes the case of outside air is contaminated,  when the occupational environment is in the open space and when there is no need for humidification. In addition, if there is a leakage of poisonous gases in the ducts used for air conditioning and heating, ventilation may not be needed since the pollutant gas can be drawn into the space through the various openings (United States Department of Labor, n.d.). Ventilation system may not be required in spaces where it would not be effective for the employees and in such cases what is required is the use of respirators and this process requires the implementation of a Respiratory Protection Program. 

Reference

United States Department of Labor (n.d.).Occupational Safety and Health Administration. Retrieved from: https://www.osha.gov/dts/osta/otm/otm_iii/otm_iii_3.html