AMCA inmotion - Fall 2017 - 6

2 in. wg

3 in. wg
FEI

BHP

RPM

BHP

Static Pressure

dling, could also have FEI requirements of less than 1.0.
in any manner they choose. A fan user can utilize any comAs shown in Table 1, high-performance-building standards bination of fan, transmission, motor and speed control if the
(such as ASHRAE Standard 189.1) or utility rebate programs combined FEI level meets the minimum requirement.3
would set FEI requirements to be greater than the baseline
Even though FEI was developed to focus on fan energy as
requirement. In the current fan efficiency provision in ASHRAE applied, it can also be used as an application-independent
Standard 189.1, additional stringency is added to the corre- metric when the design operating point is not known.2 This
sponding ASHRAE Standard 90.1 provision by making the would be true for fans sold off the shelf without a motor. In
sizing/selection window smaller - from 15 percentage points this case, FEI is evaluated at the best efficiency point at the
to 10. This is because more energy is saved by further restrict- maximum published fan speed. If the fan on the shelf has a
ing fan selections to larger sizes rather than increasing the fan motor and drive, the distributor will have the FEI bubble. By
efficiency grade (FEG) rating from 67 to
FEG 71, the next level up.7, 8
High Efficiency Fan
The FEI metric can also stand up to
Peak Efficiency
the expected increased stringency in
codes and regulations over time as fan
technology improves. The baseline FEI
can be moved from 1.0 to 1.1, for
example. This would nudge requirements
higher while also preserving the integrity
FEI 1.1
of fans labeled with FEI ratings set
previously. A fan's label showing comFEI 1.2
FEI 1.0
pliance with a requirement of FEI 1.0
today would be valid in the future if the
FEI 0.9
requirement was raised to FEI 1.2. A
building owner replacing the fan under
the future regulation would replace the
FEI 1.0 fan with an FEI 1.2 fan.
Airflow
For those looking to be rewarded for
Figure 2: Compliance bubble for a high-efficiency fan.
efficiency, the Extended Motor Product
Label Initiative (EMPLI) is developing
a rebate program for motor driven loads.2
Low Efficiency Fan
Under EMPLI, AMCA, the Hydraulics
Peak Efficiency
Institute and the Compressed Air and Gas
Institute represent fans, pumps and air
Maximum speed in
compressors, respectively, by providing
which FEI ≥ 1.0 at
best efficiency point
knowledge and experience in their given
markets. When the AMCA FEI rating
FEI 0.9
standard is complete, it should further
enable rebate program development and
implementation.
FEI 1.0

FEI 0.8

THE FINER POINTS OF FEI

While code authorities and the DOE
will establish minimum FEI (or maximum fan power) levels as they deem
appropriate, fan suppliers and users have
the freedom to meet these requirements
6

Fall 2017

FEI 0.7

Airflow

Figure 3: Compliance bubble for a low-efficiency fan.
A M C A I N T E R NAT I O NA L

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Table of Contents for the Digital Edition of AMCA inmotion - Fall 2017