Increasing ventilation for your workplace is an effective strategy since outdoor air is highly unlikely to be contaminated by the virus
that causes COVID-19. This is essentially a dilution strategy, because increasing outdoor air reduces the overall potential level of
contaminated air in your facility. This can be accomplished using permanent equipment such as wall fans, roof ventilators or the
temporary use of large mancoolers that are placed in open doors. Here are five of Airmaster’s recommendations for safely increasing
the amount of fresh air entering your facility and reducing the potential spread of contamination.
1. Do NOT Disable Ventilation Equipment.
According to American Society of Heating, Refrigerating
and Air-Conditioning Engineers’ (ASHRAE) statement
regarding the pandemic, ventilation equipment can be
used to reduce the contamination by dilution ventilation.
Additionally, “unconditioned spaces can cause thermal
stress to people that may be directly life threatening and
may also lower resistance to infection.” Here is ASHRAE’s
2. Remember to Use Common Sense when using Ventilation Equipment.
You wouldn’t think to put your car’s exhaust in your
neighbor’s window – working with air movement
during the pandemic is somewhat the same! Workers
in these environments should also still rely on the
recommended personal protection equipment (PPE)
and proper hygiene. Airflow, even when handled
properly, is not a substitute for PPE.
3. Air Velocity and Direction Should Be Used in Tandem.
High velocities can invite contamination and increase
the dispersion of contamination, so the air direction
should always flow from clean areas to areas where
contamination is not as critical, such as away from
workstations. Try to arrange the airflow pattern in such
a manner so that once it passes workstations, it is either
immediately exhausted to the exterior or it passes through
an unoccupied area where contamination is less of an
issue. When portable coolers like large mancoolers, or
barrel fans, are used for dilution ventilation, the velocity
should be allowed to dissipate with distance before air
reaches the workstation, so that the risk of carrying
contamination is reduced.
4. Cross Ventilation is an Effective Method
Where Personnel are Moving.
For situations where personnel are moving, the most
effective method is to “cross ventilate” an area with units
on one side of a plant providing supply air and units on
the opposite side of the area that are set to exhaust. This
will provide effective dilution without high velocities being
imposed on workstations. Remember to pay attention to
obstructions and heat sources!
5. For Using Air Circulators, Low Speeds and Airflow Direction Must Also be Considered.
For personal cooling equipment, using the lowest speed
setting that provides the necessary level of comfort so
that velocities are minimized, and the direction of airflow
is important. Air circulators should be positioned so that
the air flows at a right angle to the line of workstations
and that it passes from one workstation to a less clean
area. Directing the air from an elevated air circulator
downwards past the breathing zone of a worker and
continuing towards the floor is equally important.