Abstract
The savings calculation methodology from a fan
replacement project is presented in this paper. The fans
replaced are part of the underground ventilation system in a
platinum mine. Initially, 290 axial flow fans rated at 45kW were
to be replaced with carbon fibre composite fans. According to
the manufacturer, the carbon fibre construction allowed for an
optimum blade shape which results in the carbon fibre fan being
more energy efficient. However, after the first few fans were
replaced, it was discovered that the mine’s blasting activities
caused the carbon fibre fans to crack and eventually fail.
Fortunately, the manufacturer was able to produce a steel fan
with similar performance to that of the carbon composite fans
and continue replacing old fans in the mine. The savings were
independently verified according to the International
Performance Measurement & Verification Protocol (IPMVP).
This involved testing old and new fans in a BS848 test duct and
comparing the old and new fans at various operating points on
their fan curves and making adjustments for operating
conditions such as air density underground vs at the test duct. It
was found that the new fans saved 5kW on average, across a
range of operating points.