Dilution Ventilation Strategy

For years, engineers and designers have recognized these challenges and the need for a
solution. A convenient remedy emerged in which commercial box fans or stationary cooling
fans are used to circulate air.
However, this method is ultimately an ineffective answer to a very real challenge. Not only
do these fans induce little air, but they also have a very limited throw distance. Additionally,
a large number of fans are required to cover even minimal areas.
“Typically, we find engineers either include way too many of these traditional garage
circulating fans in their project design or way too few,” says Gramke. “Because they are not
designed for the application, there is no real way of quantifying their effectiveness.”
The Solution: High Induction Jet Fans
Unlike commercial box fans or stationary cooling fans, Induction Jet Fans are designed
specifically for the ventilation of underground and enclosed parking garages.
How They Work
High Induction Jet Fans produce a relatively high discharge velocity that causes the
discharge air to collide with the air in front of the fan, thrusting the air forward.
Simultaneously, the friction created draws the surrounding air along with it, resulting in the
induction effect that moves the surrounding air in the direction of the airflow.
Above: Layout of induction jet fans in underground garage application.
The induction effect ensures that the quantity of air in motion will always be considerably
larger than the quantity of air passing through the fan itself. As a result, the air volume
induced will be many times greater than the fans airflow rating.
When installed, induction jet fans are strategically placed at particular points within the car
park to both improve airflow and also save space.