Updating Buildings with Old Induction Systems...
Induction HVAC systems were very popular in the 1950s and 1960s. They were used in large
buildings where space was at a premium and the small ductwork used with the induction systems
was an advantage. The induction units were typically mounted on the floor or the wall in the
building’s perimeter zones, and concealed under enclosures built to suit the size of the units
With the emergence of variable air volume systems in response to the energy crisis in the 1970s,
induction system fell into disfavor. There were energy cost concerns as the old induction units
required very high inlet static pressure (often 1.5 – 3.0 in. w.c. or more) which imposed a
significant penalty of the systems fan energy consumption. In addition, the old induction units
produced relatively high noise levels.
Many of these older building are now in need of updating. Rather than simply replacing the old
induction units with like units, there is often an opportunity to significantly improve the
performance of the old induction HVAC system through the use of new induction units which incorporate
the latest induction nozzle technology, while re-using much of the buildings existing
infrastructure (ductwork, piping, etc).