Blinds & Shutters - Issue 4-2020

LOUVRES
Wind protection
EWT wind turbines
fitted with burglarresistant
Renson
ventilation louvres
When planning its new Westeinde wind
farm in Anna Paulowna (NL), wind
turbine manufacturer EWT realised it
needed a solution for additional heat losses in their
ever more powerful wind turbines. Needless to say,
they soon turned to Renson. One condition was
that resistance to burglaries could not be
compromised in any way by fitting ventilation
louvres to the turbines.
“The reason for our partnership with Renson
was an increase in the rated power of our wind
turbines from 900 kW to 1 MW. In addition, the
net transformer, which is usually located in an
external building, was placed inside our turbines.
This caused our heat losses to double, and we
had to compensate for this in an efficient manner,”
EWT’s mechanical engineering manager, Danny
Ferket explains. “We previously had a cooling
system in our wind turbines, but this was no
longer able to cope with the new configuration.
There were various options to compensate for
this, from increasing the airflow to reducing the
pressure drop inside the turbine – or installing a
different type of cooling altogether. We eventually
chose to fit ventilation louvres to create an
additional inflow of cooler (outside) air. This
solution offered the best balance between cost
and durability.”
On the flip side, ventilation louvres could
potentially lower the burglar resistance of the
doors in the wind turbines. Considering the fact
these turbines contain lots of metals that are
attractive to thieves, this posed a real problem.
“That’s why we were specifically looking for louvres
that complied with burglar-resistance class RC3 as
a minimum; the same class as our doors, which are
made of 8 to 12 mm of lasered stainless steel,”
Danny Ferket continues. “The dimensions of the
ventilation louvres were eventually decided by the
airspeed and the amount of space they were
continues on page 24
22 Blinds & Shutters • ISSUE FOUR 2020