Fan Performance Mark Stevens Director of Laboratory Services

Fan Performance Mark Stevens Director of Laboratory Services AMCA International The International Authority on Air System Components

Fan Testing for Air Performance The International Authority on Air System Components

AMCA Standard 210 Piezometer Ring Fan Static Pressure Test Fan Nozzles Fan Airflow Auxiliary Fan The International Authority on Air System Components

AMCA 210 Test Results 800 2. 5 700 2 500 1. 5 400 1 300 200 0. 5 100 0 2 4 6 8 Air Flow, Q The International Authority on Air System Components 10 12 Power, H Pressure, P 600

Fan Laws for Speed Change QC = ( ) ( ) NC N Q Q, Fan Airflow Rate P P, Fan Pressure H H, Fan Power 2 PC = NC N 3 HC = NC N The International Authority on Air System Components

10% Speed Change 800 2. 5 700 2 33% More H 500 1. 5 400 1 300 200 0. 5 10% More Q 100 0 2 4 6 8 Air Flow, Q The International Authority on Air System Components 10 12 14 Power, H Pressure, P 600

AMCA Standards 500 -D & -L Test Damper Piezometer Ring Damper Pressure Drop Nozzles Damper Airflow Auxiliary Fan The International Authority on Air System Components

AMCA Test. Point Results Fan 500 -D Operating 700 600 500 Pressure, P Operating Point 400 300 200 100 0 0 2 4 6 8 Air Flow, Q The International Authority on Air System Components 10 12

Speed Change 800 700 600 New Operating Point Pressure, P 500 New speed Operating Point 400 300 200 100 0 0 2 4 6 Air Flow, Q 8 The International Authority on Air System Components 10 12 14

Damper Opening 700 600 Pressure, P 500 Operating Point 400 New Operating Point 300 New System 200 100 0 0 2 4 6 8 Air Flow, Q The International Authority on Air System Components 10 12

System Effect • Installed duct configuration does not match tested duct configuration • Detrimental effect on fan air performance due to adverse flow conditions at the inlet or outlet of a fan The International Authority on Air System Components

Installation Type D Ducted Inlet / Ducted Outlet Piezometer Ring Fan Static Pressure Test Fan Nozzles Fan Airflow Auxiliary Fan Plenum Installed Fan The International Authority on Air System Components

AMCA Catalog Ratings • “Performance certified is for installation type: ◦ ◦ A: Free inlet, Free outlet” B: Free inlet, Ducted outlet” C: Ducted inlet, Free outlet” D: Ducted inlet, Ducted outlet” The International Authority on Air System Components

System Effect • Even when the tested duct configuration matches the installed duct configuration, improper duct design can introduce adverse flow conditions The International Authority on Air System Components

Elbow Example The International Authority on Air System Components

Detailed Plenum Example Plenum The International Authority on Air System Components

Detailed Plenum Example • Centrifugal Fan • Airflow Rate Cutoff ◦ 14. 4 m 3/s Blast Area Outlet Area • Blast Area/Outlet Area ◦ 0. 6 • Velocity ◦ 14. 4 m/s The International Authority on Air System Components

Detailed Plenum Example E-F duct friction at 5000 CMH (Q) E contraction loss-plenum to duct E PS energy required to create velocity at E D PV loss (also PT loss) at D as result of air velocity decrease 747 Pa (duct design) 50 Pa (part of duct system) 125 Pa (part of duct system) 0 Pa PS does not change from duct to plenum at D C-D outlet duct on fan as tested 0 Pa ---------- REQUIRED Fan PS 922 Pa The International Authority on Air System Components

Detailed Plenum Example D-E duct friction at 5000 CMH (Q) D contraction loss-plenum to duct D PS energy required to create velocity at D B-C SEF 747 Pa (duct design) 50 Pa (part of duct system) 125 Pa (part of duct system) 149 Pa B-C PV loss (also PT loss) at C as result of air velocity decrease 0 Pa PS does not change from duct to plenum at C --------- REQUIRED Fan PS 1071 Pa The International Authority on Air System Components

Detailed Plenum Example Calculation of SEF of 149 Pa From AMCA Publication 210 No Duct From Figure 8. 3 12% Effective Duct 25% Effective Duct 50% Effective Duc t 100% Effective Duct Outlet Duct Blast Ar ea Sys tem E ffe ct C urve O utle t Area 100% Effective Duct Length 0. 4 P R -S U W -- 0. 5 P R -S U W -- 0. 6 R -S S -T U- V W- X -- 0. 7 S U W -X -- -- 0. 8 T-U VW X -- -- 0. 9 W -W W -X -- -- -- 1. 0 -- -- -- The International Authority on Air System Components

Using line R from Figure 7. 1 14. 4 m/s The International Authority on Air System Components

Plenum Example from AMCA 201 Assuming: • Use of the same fan for both systems • Can attain both operating points with a change in speed • The increased in power consumption to overcome System Effect is about 25% ◦ (1071/922)0. 5 = 1. 08 (Fan Law for pressure) ◦ 1. 083 = 1. 25 (Fan Law for Power) The International Authority on Air System Components

Ducted Fan as Tested C-D duct friction A free inlet B-C outlet with straight duct attached for 2 or more diam. 750 Pa (duct design) 0 Pa (no SEF) ---------- REQUIRED Fan PS 750 Pa The International Authority on Air System Components

Ducted Fan Exhaust System A A-B B C E Entrance loss-sharp edge duct Duct friction at 5000 CMH SEF 1 (Elbow at Inlet) SEF 2 (Obstruction) SEF 3 (Abrupt Discharge) REQUIRED Fan Ps 100 Pa (duct design) 750 Pa (duct design) 150 Pa --------- 1200 Pa The International Authority on Air System Components

Deficient Fan/System The International Authority on Air System Components

Speed Changes • Before Increasing Speed ◦ Check with the manufacturer for max safe operating speed ◦ Determine expected power increase • Motor size • Electric Service ◦ Expect more noise The International Authority on Air System Components

Rules of Thumb • Minimum 2. 5 duct diameters on Outlet • Minimum 3 to 5 duct diameters on Inlet • Avoid inlet swirl The International Authority on Air System Components

Recommendations • Allow enough space in the building design to allow for appropriate fan connections to the system The International Authority on Air System Components

Recommendations • Use allowances in the design calculations when space or other factors dictate less than optimum arrangement of the fan outlet and inlet connections The International Authority on Air System Components

Recommendations • Include adequate allowance for the effect of all accessories and appurtenances on the performance of the system and the fan The International Authority on Air System Components

The International Authority on Air System Components

Thank you AMCA International, Inc. 30 W. University Drive Arlington Heights, IL 60004 USA Tel: +1 847 394 0150 Fax: +1 847 253 0088 www. amca. org Mark Stevens - mstevens@amca. org The International Authority on Air System Components