BUILDING TECHNOLOGIE

April 29‐30, 20

ASRAC Pumps Working Group

Metric: Testing and Calculations
2

Primary Discussion Review of Metric and Relationship to Standard

 Overview of PER Test Procedure for Controlled versus Uncontro

Other Remaining Issues/Topics

 Test Procedure Options

• Calculation‐based method

- How to account for motor efficiency at part load and controls

• Testing‐based method

 Load Point Options

 Weighting Options Other Denominator Options

Overview
3

Metric Goals

1. Be objectively measureable

2. Represent the

performance of thecovered product

3. Differentiate performance among pump

models and pump configurations

(e.g. pumps sold with controls)

4. Communicate information

about pump performance tothe consumer

– May not be all the information

a consumer uses to make adecision

5. Compare the

efficiency ofa given pump

model to aminimum standard level

Metric

Test

Procedure

Tested

Performance

of Pump A

Tested

Performance

of Pump B

Bare Pump

Efficiency

or Energy

Use

Mot

Efficie

or En

Us

‘Pump’

Efficiency

or Energy

Use

=
4

Metric

Test

Procedure

Tested

Performance

of Pump A

Tested

Performance

of Pump B

Scope of Slides• This slide deck and the PER Calculator address how t

is calculated in the test procedure for a given pump 
5

Metric Applicability to Pump Configurations

Pump Configuration

Bare Pump* Bare Pump + Motor Bare Pump + 

Metric CoverageBare Pump MEI Does not include motor efficiency Does not d

losses 

Bare Pump + Driver PERCL (w/ std. driver) PERCL Does not d

losses 

Bare Pump + Driver +

Controls

PERCL

(w/ std. driver

and controls)

PERCL

(w/ std. controls) P

Pump Motor

Pump Control M

• Define a unique, but similar, metric for controlled versus uncont

pumps

• Uncontrolled pumps ‐> Constant Load Pump Energy Rating 

• Controlled pumps ‐> Part Load Pump Energy Rating (PERPL)

*Pumps sold with non‐electric drives could be rated as

bare pumps
6

PER Test Procedure

Pump Energy Rating (PER) CL and FL: equally weighted average el

power to the ‘pump’ measured (or calculated) at the driver input o

present, controls input, over a specified load profile:

Where:

• PER = Pump Energy Rating (hp);

• wi = weight at each load point i;

• LCF = Load Control Factor (dimensionless);

• Pini = power input to the “pump” at the driver, inclusive of t

if present, (hp);

• Denominator = minimally compliant uncontrolled pump; an

• i = Percentage of flow at the best efficiency point (BEP) of th

• i = 110%, 100%, 75% of Best Efficiency Point (BEP) flow 

speed for uncontrolled pumps

• i = 25%, 50%, 75%, and 100% of BEP flow at nominal sp

pumps sold with motors and controls.

ࡲ࡯ࡸ ൌ ࡸࡲ/ࡸ࡯ࡾࡱࡼ

∑ ߱௜ ܲ௜௡ ௜ ௜

ܲ	݈݈݁݀݋ݎݐ݊݋ܷ݊ܿ	ݐ݈݅ܽ݊݌݉݋ܥ	ݕ݈݈݅݊݅݉ܽܯ

8

Minimally Compliant Pump

• PER for a minimally compliant pump

– Based on PER Standard set through Standards analysis ≈MEI10 assumed for 

– Assumes a pump curve shape for the minimally compliant pump and always 

controls

– Motor losses are that of a minimally compliant enclosed motor for the appr

– The minimally compliant pump efficiency is calculated for each pump type b

of flow and speed

ܲܧܴ ௡௜௠ൌ ߱଴.଻ହ

ܲு௬ௗ௥௢,଴.଻ହ

0.95 ∗ ߟ௣௨௠௣ ൅ ܮ଴.଻ହ ൅ ߱஻ா௉

ܲு௬ௗ௥௢,஻ா௉

௣௠௨௣ߟ

൅ ܮ஻ா௉ ൅ ߱ଵ.ଵ

ܲு௬ௗ

0.985 ∗ 

ܨܥܮ	PERൌ

߱଴.଻ହ ܲ௜௡଴.଻ହ ൅ ߱஻ா௉ ܲ௜௡஻ா௉ ൅ ߱ଵ.ଵ ܲ௜௡ଵ.ଵ

߱଴.଻ହ

ܲு௬ௗ௥௢,଴.଻ହ

0.95 ∗ ߟ௣௨௠௣ ൅ ܮ଴.଻ହ ൅ ߱஻ா௉

ܲு௬ௗ௥௢,஻ா௉

ߟ௣௨௠௣ ൅ ܮ஻ா௉ ൅ ߱ଵ.ଵ

ܲு௬ௗ

0.985 ∗ 

ൌ 1

13 ∗ ܲ଴.଻ହ ൅ ܮ଴.଻ହ ൅ 13 ∗ ܲ஻ா௉ ൅ ܮ஻ா௉ ൅ 13 ∗ ܲଵ.ଵ ൅ ܮଵ.ଵ

13 ∗

ܲு௬ௗ௥௢,଴.଻ହ

0.95 ∗ ߟ௣௨௠௣ ൅ ܮ଴.଻ହ ൅ 13 ∗ ܲு௬ௗ௥௢,஻ா௉ ߟ௣௨௠௣ ൅ ܮ஻ா௉ ൅ 13 ∗ ܲு௬ௗ௥

0.985 ∗ 
9

Determining Minimally Complaint Pump Efficie

ߟ௣௨௠௣ ൌ 88.59 ∗ ln ܰݏ ൅ 13.46 ∗ ln ܳ௠௘௧௥௜௖ െ 11.48 ∗ ln ܰ

∗ ln ܳ ଶ െ 0.38 ∗ ln ܰݏ ∗ ln ܳ െܥ

• Where:

– Ns is the specific speed of the pump in metric units,

– Q is the flow rate of the pump at BEP in m3/hr,

– C is the C‐value of the surface, which is set based on the speed of 

the pump, and

– All values are for the pump at 50 Hz. C‐Values to Determine Pu

Pump Type Speed M

ESCC 1800 1

ESFM 1800 1

IL 1800 1

RSV ALL 1

VTS ALL 1

ESCC 3600 1

ESFM 3600 1

IL 3600 1
10

Determining PERFL for a Controlled Pump

ܨܥܮ ൌ ܴܧܲ

߱଴.଻ହ ܲ௜௡଴.଻ହ ൅ ߱஻ா௉ ܲ௜௡஻ா௉ ൅ ߱ଵ.ଵ ܲ௜௡ଵ.ଵ

௡௜௠ܴܧܲ

ൌ

1

η௖௧௥௟

߱଴.ଶହ ܲ௜௡଴.ଶହ ൅ ߱଴.ହ଴ ܲ௜௡଴.ହ଴ ൅ ߱଴.଻ହ ܲ௜௡଴.଻ହ ൅ 

௡௜௠ܴܧܲ

LCF Approach Full Calculation Approach

PumpPerformance

Pi = measured shaft input power to the pump

(speed x torque) at each load point i

Where: i = 75%, 100%, and 110% of flow rate at

BEP of the pump and equal weighting

Pi = calculated shaft input p

based on affinity laws at ea

Where: i = 25%, 50%, 75%, 

rate at BEP of the pump and 

MotorPerformance(Losses)

Lrated is the full load losses of a motor that is paired with the pump and losses are 

reduced loading with speed reduction

ControlsPerformance

LCF = 0.56 for VFD control, 0.67 for 2‐speed

motor, etc.

Accounts for reduced power input at load points

of 25%, 50%, 75% and 100% of BEP flow

Drive efficiency = 96%

Benefit is captured in calcul

input power.

Could still account for drive 
11

Pump Hydraulic Output Power• Pump Hydraulic Output Power

– “Denominator” = hydraulic output power at each load poin

• Note, this example also flips the numerator and denominator 

higher values “better.”

• Units = dimensionless

ൌ ܴܧܲ

1

௜ ௜ܮ ൅ ௜ܲ ௜,௢௥ு௬ௗܲ௜ ߱ ෍ ܨܥܮ
12

House of Efficiency versus Weighted Average

House of Efficiency Weighted Average

Characteristics • Defines pump performance

uniquely at individual load

points

• Weights pump p

all load points to 

single metric

Pros • Potentially more informative

for the market

• Similar to EU approach

• More accommo

different pump 

• Simpler to comp

Cons • Less flexible, since a

manufacturer has to meet all

load points

• Masks performa

individual load p

Other Comments • Could potentiall

points on label odatabase

Working Group Recommendation =
13

Metric Nomenclature• Pump Energy Rating (PER)

• Pump Efficiency Rating (PER)• Pump System Energy Rating (PSER)• Pump System Efficiency Rating (PSER)• Others?
14

PER Test Procedure Options

Pump Configuration

Bare Pump* Bare Pump + Motor Bare Pump + 

Test Procedure Options

Tested BarePump +

Calculations

Tested bare pump

performance + DOE

minimum efficiency

motor with assumed

part load losses

Tested bare pump

performance +

manufacturer motor

with assumed part

load losses

Tested 

performance 

motor with as

losses + Load 

Tested Pump

withManufacturerMotor

N/A

Tested performance

of bare pump with

manufacturer motor

(wire to water)

Tested perfo

pump with 

motor (wire t

Contr

Tested Pump

with Motorand Controls

N/A N/A

Tested perfo

pump with 

motor and c

syste

Pump Motor

Pump Control M

*Pumps sold with non‐electric drives could be rated as bare pumps
15

Determining Pump Input Power

Power input to the pump at a specific load point (Pini) can be:

(A) measured using a wire to water test; or

(B) calculated as the power input to the pump (Pi) plus the motor 

that load point:

Where:

• Pini = power input to the “pump” at the driver, inclusive o

controls if present (hp);

• Pi = the shaft input power to the bare shaft pump (hp);

• Li = the fractional load motor losses (hp); and

• i = Percentage of flow at the best efficiency point (BEP) of 

Expanding the PER equation yields the following equation:

௜ܮ ൅ ௜ܲ ൌ௜௡௜ ܲ

ݎ݋ݐ݉݅݊ܽ݋݁݊ܦ ௜ܮ ൅ ௜ܲ ௜߱ ௜∑ ܨܥܮ ൌ ܴܧܲ
16

Accounting for Motor Losses

The fractional motor losses at each load point i (Li) are calculated as the ra

motor losses (Lrated) multiplied by the part‐load loss factor (yi), which is calcubic polynomial* of the load fraction on the motor (xi):

ܮ ௜ൌ ܮ௔௥௧௘ௗ ∗ ݕ݅ ൌ ܮ௔௥௧௘ௗ ∗ ܽ∗ݔ௜ଷ ൅ܾ∗ݔ௜ଶ ൅ܿ∗ݔ ൅ ௜݀

ൌ ܮ௔௥௧௘ௗ ∗ ܽ ∗

ܲ௜

݁ݖܵ݅ݎ݋ݐ݋ܯ

ଷ

൅ܾ∗

ܲ௜

݁ݖܵ݅ݎ݋ݐ݋ܯ

ଶ

൅ܿ∗

ܲ௜

ݎ݋ݐ݋ܯ

Where:

• Li = the fractional load loss of the motor at load point i (hp);

• Lrated = the rated full load motor losses as determined in accorda

DOE test procedure for motors at 10 CFR 431 subpart B (hp);

• yi = the part‐load loss factor;

• xi = the load fraction for the motor at each load point i;

• Pi = the shaft input power to the bare shaft pump (hp);

• MotorSize = the nominal rated output power of the motor (hp); 

• i = Percentage of flow at the best efficiency point (BEP) of the pu

*A different cubic polynomial (i.e. different a, b, c, and d coefficients) are a

based on the rotating speed (2‐pole vs. 4‐pole) and motor design (ODP vs
17

Testing Bare Pump Performance

Perform HI 40.6 to determine bare shaft input power at each load point i:

• 7 points swept from shutoff to maximum flow rate, with flow rate (GPM

rotational speed (rpm), torque (in‐lbf) recorded in following table

• Hydraulic pump efficiency is calculated at each flow point

– Input power = (torque) x (speed)

– Output power = (flow rate) x (head) x (specific weight of fluid)

– Efficiency = output power / input power

• BEP found by determining maximum of best fit curve of efficiency with 

rate

• Bare shaft input power at each load point found by interpolating perfor

pump curve at 75% and 110% of BEP flow

% of BEP

flow

Flow Rate

(GPM) Head (ft)

Speed

(RPM)

Torque

(lb‐in)

Hydraulic

Power

(hp)

Shaft input

power (hp) η

128 1200.59 141.51 1774.10 1977.14 41.76 55.65 7108 1012.80 157.91 1774.63 1782.87 39.31 50.20 78100 939.62 162.58 1774.80 1721.36 37.55 48.47 77

91 851.24 169.44 1775.86 1613.80 35.46 45.47 776 709.87 178.40 1775.85 1458.85 31.13 41.11 758 547.19 186.61 1777.84 1251.15 25.10 35.29 748 449.06 189.67 1778.80 1112.42 20.94 31.40 6
18

×

standardized motor

efficiency and default

part load curve

MOTOR

pump performance data

from pump test at rated

speed

Determining Bare Pump PER

×

standardized co

performance 

Controls

• Pi values are the tested shaft input power to the pump (speed x torque) at eac

• i = 75%, 100%, and 110% of flow rate at BEP of the pump

• Equal weighting

• Standardized Motor Performance

• Enclosed motor that is minimally compliant with DOE’s motor regulation

for general purpose motors (subtype I) for all pumps except ESCC and ge

motors (subtype II) for ESCC pumps

• HP used will be next HP above brake horsepower at 120% of BEP HP

• Poles will be based on speed at which pump is being rated

• Standardized Controls Performance

• LCF = 1 (no controls)

• Drive efficiency = 100% (since no drive)
19

×

manufacturer motor

efficiency at full and part

load

MOTOR

Bare Pump + Motor Test Procedure

Ma

pai

wit

pump performance 

data from pump

test at rated speed

standardized

controls

performance = 1

Controls ×

MOTOR PUMP

Ma

me

p

standardized

controls

performance = 1

Controls

×

pump+motor performance data

A

B
20

pump performance from pump test at

rated and reduced speed

×

motor/drive performance

data

BC

VFD MOTOR

Controls MOTOR PUMP

Bare Pump + Motor + Controls Test Procedure

Ma

pai

mo

Ma

me

p

co

×

manufacturer or default

motor efficiency

A MOTOR

Ma

pai

with 

m

de

pump performance

data from pump test

at rated speed

default controls

performance

× Controls
21

Load Control Factor: Basis

 LCF is defined as the ratio of PER of a speed controlled pump to 

uncontrolled pump

• ܨܥܮ ൌ 	 ௉ாோ಴೚೙೟ೝ೚೗೗೐೏

௉ாோೆ೙೎೚೙೟ೝ೚೗೗೐೏

• Load control factor for the VFD provided in PER calculation examp

depending on load profile and weighting

 PER of pump+motor will be used to determine the LCF for each 

 Use an assumed conservative system curve for all three options 

variations to determine the Load Control Factor

 Assumptions:

• Efficiency of control = 96%

૚ࡽ૛ࡽ

ൌ

૚࢔૛࢔

૚ࡴ૛ࡴ

ൌ

૚࢔૛࢔

૚ࡼ ૛૛ࡼ

ൌ

૚࢔૛࢔

૜
22

Load Control Factor Options• Other control options to be considered?• Make LCF a function of efficiency to distinguish simil

options with different efficiencies?

Control Efficiency of Control Other Assumptions 

VFD 96% Follow defined system curve 

ECM 96% 2‐speed motor 96%

25% and 50% load point are at

lower speed & 75% and 100%load points are at full speed
23

Control Load Curve• Load curve in PER calculator: dynamic head based load curve

– Head vs flow is proportional: ܪ	 ∝ 	ܳ2

• Proposed: load profile with a static offset

– Head with flow is offset: ܪ ൌ ߙܳଶ ൅ ܪௌ௧௔௧௜௖– Assume: static offset is 20% of BEP head (other offsets could be c

– Given QBEP and HBEP, the system curve becomes:

• ܪ ൌ 0.8 ுಳಶು

ொಳಶುమ ܳଶ ൅ 0.2ܪ஻ா௉

• This curve passes through both BEP and the pump head intercept at 

0

50

100150200250300350

0 200 400 600 800 1000 1200 1400

Head (ft)

flow rate (GPM)

Original VFD load profileNew VFD Load ProfileExample Pump Curve

Best Efficiency Point

20% of BEP Head

Realized potential savings

Unrealized savings
24

Impact of Static Load Profile• More realistic representation of how controls are use

• Using static offset curve will produce more conserva

estimate of PER using calculation method

– Testing will proceed with closed loop (dynamic system curv

therefore tested PER values should consistently outperform 

obtained from calculation method
25

Impact of Static Offset on PER• Results of PER calculation for bare shaft pump with motor and 

original load curve is compared to static offset load profile to s

increased energy consumption due to unrealized savings

Load Profile

PER (hp) Percen

Increase i

with Static 

Curve

Original Load Curve Static Offset Load Curve

50, 75, 100,

110 (equal

weighting)

34.61 36.37 5.1%

25, 50, 75,

100 (equal

weighting)

21.36 23.70 11.0%

75, 100, 110

(equal

weighting)

43.07 44.16 2.5%
26

Application of Calculation and Testing Based M• Is physical testing more appropriate for some equipment classe

calculation method is more appropriate for others?

– e.g. ESCC pumps, pumps sold with non‐DOE motors

Test Method Pros ConsCalculationMethod

Repeatable;Less burdensome

Does not differentiat

controls performancAssumptions regardi

motor/controls effici

changing load requir

Decreased accuracy

Physical TestMethod

Accurate;Differentiates performance of

different motor/controlsequipment at full and part load

Burdensome;AHRI 1210 test data 
27

• Load points assuming equal weighting:• Choice of load points does not impact ranking, only r

magnitude

– Fewer low‐end load points de‐emphasizes impact of contro

Impact of Different Load Points

Load Profile

Pump Energy Rating (PE

Bare

Pump

Pump & 95%

Eff. Motor

Pu

M

75%, 100%, 110% of BEP flow 49.48 48.65 

25%, 50%, 75%, 100% of BEP flow 39.31 38.51 

50%, 75%, 100%, 110% of BEP flow 45.95 45.14 
28

Load Profiles

• Very little field data is available regarding typical load 

and load profiles are extremely variable based on app

• PER calculated based on 4 typical load profiles

– LP0: BEP only

– LP1: equally weighted at 75%BEP, BEP, 110%BEP

– LP2: increasing load, peak at BEP

– LP3: increasing load, peak at BEP, with overload at 110@BEP

0

0.20.40.60.8

1

50%BEP 75%BEP 100%BEP 110%BEP

WeightsLP0 LP1 LP2

LP3
29

• Assume load points of 50%, 75%, 100% and 110% of • Weightings impact magnitude of calculated PER and 

relative impact of controls, but do not change relativ

comparison of pump configurations or ranking

Impact of Different Weightings

Load Profile

Pump Energy Rating (PE

Bare

Pump

Pump & 95%

Eff. Motor

Pu

M

LP0: 100% BEP Flow Only 51.06 50.21 

LP1: Equal Weighting 45.95 45.14 

LP2: Increasing Load, Peak at BEP 45.93 45.12 

LP3: Increasing Load, Peak at BEP with

Overload at 110@BEP

46.65 45.84 
30

Big change in r

need to consider non 

Relatively consistent 

as multiple load poin

0

200400600800

100012001400160018002000

0 500 1000 

Ranking based on PER LP3

Ranking based on PER LP1 [0.33@

0

200400600800

100012001400160018002000

0 500 1000 1500 2000

Ranking based on PER LP2

Ranking based on PER LP1

[0.33@0.75BEP,BEP,1.1BEP]

0

200400600800

100012001400160018002000

0 500 1000 1500 2000

Ranking based on PER LP1

Ranking based on PER LP0 [1.00@BEP]

Impact of Weighting on Relative Ranking
31

“Denominator” Options

“Denominator” Units Pros ConsNo Denominator Hp or kWh

Representative of the energy

consumption of that pump in thefield.Strong function of flow and specific

speed.

Not comparabl

different flows/

Less strong funspecific speed.

Reference shaft power

for minimally

compliant bare pumpwith minimally

compliant motor

Dimensionless

Results in value between 0 and 1

(more intuitive).Clearly indicates performance of a

pump relative to a baseline.

Inherently requ

minimally comp

MEI). May ovethe baseline eff

pumps.

Market average shaft

power with minimally

compliant or market

average motor

Dimensionless Indicates performance of a pump

relative to the market.

Locks in the me

performance of market at a give

Doesn’t limit m

0 and 1.

Tested pump’s

hydraulic power at

BEP

Dimensionless

Accounts for differences in pump

efficiencies between models.

Has similar rated values for pumpsof different sizes.

Lower PER ratin

because lower 

is inherently les
32

Denominator Options Comparison• Assumptions

– Load point

• 75%, 100%, and 110% of BEP flow for bare pump and bare pump + motor

• 25%, 50%, 75% and 100% for controlled pump

– Weighting

• equal weighting

– System Curve

• Affinity laws

Denominator

Scaling Options Value (hp)

Pump energy rating (PER

Bare Shaft

Pump

Pump & 95%

Eff. Motor

Pum

Mo

No Denominator N/A 49.48 48.65 

Hydraulic power Calculated at each load point 0.719 0.732 

Minimally

Compliant

(MEI10)

52.74 0.938 0.922 

Market Average

(MEI50) 48.89 1.012 0.995 
33

Market Average Pump

• Market Average Pump

– Denominator = PER for a market average pump

• Based on ≈MEI50 for U.S. market

• Assumes a pump curve shape for the minimally compliant pump and a

assumes no controls

• Motor losses are that of a minimally compliant enclosed motor for the 

pump type

• The market average pump efficiency is calculated for each pump type 

function of flow and speed

• Units = dimensionless

ܨܥܮ ൌ௚ ௩௔ܴܧܲ

߱଴.଻ହ ܲ௜௡଴.଻ହ ൅ ߱஻ா௉ ܲ௜௡஻ா௉ ൅ ߱ଵ.ଵ ܲ௜௡ଵ.ଵ

߱଴.଻ହ

ܲு௬ௗ௥௢,଴.଻ହ

0.95 ∗ ߟ௣௨௠௣ ൅ ܮ଴.଻ହ ൅ ߱஻ா௉

ܲு௬ௗ௥௢,஻ா௉

ߟ௣௨௠௣ ൅ ܮ஻ா௉ ൅ ߱ଵ.ଵ

ܲு௬ௗ௥

0.985 ∗ 

ൌ 1

13 ∗ ܲ଴.଻ହ ൅ ܮ଴.଻ହ ൅ 13 ∗ ܲ஻ா௉ ൅ ܮ஻ா௉ ൅ 13 ∗ ܲଵ.ଵ ൅ ܮଵ.ଵ

13 ∗

ܲு௬ௗ௥௢,଴.଻ହ

0.95 ∗ ߟ௣௨௠௣ ൅ ܮ଴.଻ହ ൅ 13 ∗ ܲு௬ௗ௥௢,஻ா௉ ߟ௣௨௠௣ ൅ ܮ஻ா௉ ൅ 13 ∗ ܲு௬ௗ௥௢,ଵ.ଵ 0.985 ∗ ߟ௣௨௠௣ ൅