Dr. Michael Brendel

Lau Industries/Ruskin Company Dayton, OH

USA

Fan Efficiency Grade Classification for Fans

ASHRAE Annual Meeting 2012 San Antonio, TX

1. Describe Fan Efficiency Grade (FEG). 2. Describe the use and application of FEG. 3. Explain FEG for selection of efficient fan. 4. Provide an overview of how FEG will be used in the fan industry in the very near future. 5. Explain how standard and regulatory authorities will utilize FEG for setting requirements. 6. Describe the impact of FEG on fan technologies.

Learning Objectives

ASHRAE is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to ASHRAE Records for AIA members. Certificates of Completion for non-AIA members are available on request.

This program is registered with the AIA/ASHRAE for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Outline

•  Background •  Fan Energy Metrics •  Fan Efficiency •  FEG - Fan Efficiency Grade •  ASHRAE 90.1 and FEG

US Energy Consumption 2010* = 98 Quads (104 EJ)

•  Equivalent to 29 million million kWh •  37% from petroleum transportation •  21% from coal electricity •  25% from natural gas residential, commercial, industrial •  Over half of source energy rejected (heat)

FOCUS ON AIR DISTRIBUTION

•  Estimated: DOE ~230 billion kWh for commercial/industrial fans •  Estimated: ~20% commercial building energy budget

*source LLNL

Energy Consumption

Q

system system equipment

Flow

Ene

rgy

per U

nit V

olum

e (P

ress

ure)

TP

SP

VP

FAN

FTP = fan total pressure (PT)

FSP = fan static pressure (P)

FVP = fan velocity pressure (Pv)

HVAC System

Fan Energy Consumption

Fan Shaft Power, H (input)

Aerodynamic Losses

Mechanical Losses

Acoustic Loss

Air Power, Ho ≡ PT Q

Energy Efficiency ≡

25” Belt Drive Airfoil DWDI Blower Operating Point: 16,800 cfm @ 6.5 in-wg (total), 21.5 bhp, 80% FTE Operating Conditions: 50% duty cycle, $0.15/kWh Motor - 90% efficient, Drive - 90% efficient

Motor Loss ($1,302)

Aerodynamic Loss ($1,302)

Acoustic Loss (80 dB 0.1 mW, <<1%)

Motor Input Power $13,016

Air Power $8,435

Shaft Power $10,543 Motor Output Power

$11,714 Fan Bearing Loss ($807)

Drive Loss ($1,171)

Drive Motor Fan

Fan Energy Consumption - Example

Annual Cost

Normalized Flowrate, Q

Fan

Tota

l Effi

cien

cy, F

TE

Impeller Diameter, D

Pea

k To

tal E

ffici

ency

, pTE

D

Fan Energy Efficiency

D1

D2

Minimum Fan Efficiency? eliminate small fans

gap = 1/4” (6 mm)

inlet cone wheel cone

Small Diameter Impeller

wheel

Fan Energy Efficiency

Large Diameter Impeller

flow separation

Effect of Manufacturing Tolerances

•  0.9% 27” (685 mm) impeller •  2.5% 10” (254 mm) impeller

Grading Standards

ISO I2759 Fans - Efficiency Classification for Fans

AMCA 205 Energy Efficiency Classification for Fans

Fan Energy Efficiency

FEG 85 FEG 80 FEG 75 FEG 71 FEG 67 FEG 63 FEG 60 FEG 56 FEG 53 FEG 50

Fan Efficiency Grade (FEG)

0 5 10 15 20 25 30 35 40

Peak

Fan

Tot

al E

ffici

ency

, pTE

(%)

90

80

70

60

50

40

30

20

Impeller Diameter (in)

Fan Efficiency Grade

15” Diameter impeller, pTE = 60% FEG = 67

FEG

Belt Drive Fan

Drive Motor Fan

Fan Efficiency Grade

FEG

Motor Fan

Direct Drive Fan

ASHRAE 90.1 – 2010: Fan Power Limitation (Tables 6.5.3.1.1A/B)

•  Two Options motor nameplate hp & bhp •  Two Systems CV & VAV

α = coefficient (hp/cfm), e.g. 0.0013 for VAV systems A = pressure drop adjustment (hp) Qs = max design supply air (cfm) H = bhp

Fan Power Limitation

Based on Specific Fan Power (SFP) approach

α = limit, e.g. 0.0013 for VAV systems B = A/Qs Qs = max design supply air (cfm) H = bhp

Encourages low pressure drop and/or high fan efficiency

Fan Power Limitation

Single fan

Fan Total Pressure (in-wg) [system restriction]

Fan

Tota

l Effi

cien

cy (%

)

Fan Power Limitation

0.4 0.6 0.8 1.0 1.2 100

90

80

70

60

50

40

30

20

10

0 0 1 2 3 4 5 6 7 8

1.4

1.6

1.8

2.0 2.2

SFP (hp/kcfm)

SFP (hp/kcfm)

Non-compliant

Single fan example: 5 in-wg TP fan must be >60% FTE (VAV, bhp option)

Fan Total Pressure (in-wg) [system restriction]

Fan Power Limitation + FEG

0.4 0.6 0.8 1.0 1.2 100

90

80

70

60

50

40

30

20

10

0 0 1 2 3 4 5 6 7 8

1.4

1.6

1.8

2.0

2.2

SFP (hp/kcfm)

Non-compliant

Pea

k Fa

n To

tal E

ffici

ency

(%)

0 10 20 30 40

90

80

70

60

50

40

30

20

Impeller diameter (in)

Peak Fan Total Efficiency (%)

FEG Diagram

≥ FEG67

10” 15” 20” >25”

Proposed minimum FEG67 + exclusions + 15pt selection condition + (> 5 hp motor)

Flowrate

Fan

Tota

l Pre

ssur

e,

Fan

Tota

l Effi

cien

cy

pTE FTP

FTE

…design point of operation shall be within 15 pts of the maximum total efficiency of the fan.

0 pts

Fan Power Limitation + FEG

Flowrate

Fan

Tota

l Pre

ssur

e,

Fan

Tota

l Effi

cien

cy

pTE FTP

FTE

…design point of operation shall be within 15 pts of the maximum total efficiency of the fan.

2.5 pts

Fan Power Limitation + FEG

Flowrate

Fan

Tota

l Pre

ssur

e,

Fan

Tota

l Effi

cien

cy

pTE FTP

FTE

…design point of operation shall be within 15 pts of the maximum total efficiency of the fan.

5 pts

Fan Power Limitation + FEG

Flowrate

Fan

Tota

l Pre

ssur

e,

Fan

Tota

l Effi

cien

cy

pTE FTP

FTE

…design point of operation shall be within 15 pts of the maximum total efficiency of the fan.

10 pts

Fan Power Limitation + FEG

Flowrate

Fan

Tota

l Pre

ssur

e,

Fan

Tota

l Effi

cien

cy

pTE FTP

FTE

…design point of operation shall be within 15 pts of the maximum total efficiency of the fan.

15 pts

Fan Power Limitation + FEG

Fan Total Pressure (in-wg) [system restriction]

Fan Power Limitation + FEG

Proposed minimum FEG67 + exclusions + 15pt selection condition + (> 5 hp motor)

0.4 0.6 0.8 1.0 1.2 100

90

80

70

60

50

40

30

20

10

0 0 1 2 3 4 5 6 7 8

1.4

1.6

1.8

2.0

2.2

SFP (hp/kcfm)

15 pts

Fan

Tota

l Effi

cien

cy (%

)

0 10 20 30 40

90

80

70

60

50

40

30

20

Impeller diameter (in)

Peak Fan Total Efficiency (%)

FEG Diagram

≥ FEG67

•  Fan energy consumption – regulation on the horizon •  Fan Efficiency – only part of the story •  FEG – aerodynamic indicator, focus on fan performance •  ASHRAE 90.1 has implicit fan efficiency requirement •  ASHRAE 90.1 + FEG proposed •  ASHRAE 90.1 generous operating efficiency band

Summary

Questions