RZ eta-engl Kopie - HOWATHERM

4
Optimized design
The ETA fan system is one of the most
technologically advanced members of our
central AHU range with energy-optimized
drive systems.
A comparison of the characteristic curves
between the energy-optimized ETA SYSTEM
and the conventional (standard) fan KZG
SYSTEM reveals the difference: depending
on the installation situation, the savings
potential varies between approx. 15% at a
static pressure increase of 1000 Pa and
about 40% at 400 Pa.
In conventional systems with spiral housing
fans, a factor of 2 to 3 times the
dynamic pressure can be viewed as pressure
loss for the fan section.
The ETA SYSTEM relies on the use of single-intake
fans without spiral casing (plug
fan type). The key benefits of this design
are that dynamic pressure levels will
account for a lower portion of the total
pressure and that inflow and outflow pressure
losses are reduced.
Since the belt drive has thus been made
redundant, the fan and motor are combined
into a single compact unit. The nonencased
impeller is mounted overhung on
the motor shaft. This design eliminates losses
due to, e.g., the belt pulley and bearing
support struts in the fan intake, belt
guards, wall influences, that means flow
losses plus belt-related losses are minimized
if not eliminated.
We recommend the use of the ETA
SYSTEM, regardless of volume flow, at
total pressure levels up to 2000 Pa. The
dynamic portion of the total pressure increase
is relatively large at low pressures,
so energy savings will be smaller.
With the direct drive system mechanical
losses are reduced, caused by the belt
drive. Also speed control is achieved via a
frequency converter integrated into the
AHU. By using an asynchronous motor of
increased efficiency, an additional 3 - 10%
power consumption can be saved depending
on system type (class EFF1 / EFF2).