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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 1 of 8 1 OBJECTIVE
To lay down a procedure for the Duct Leakage Test
Duct leak testing is to find out actual quantity of air leaking
out through duct system and
checkingthe same with standard leakage rate so as to confirm
whether leakages in the
system are within limits.
2 SCOPE:
This SOP is applicable for checking Air leak rate from G. I.
Ducting.
3 PROCEDURE:
The leak testing rig consist of a fan with fan motor, flow
measuring arrangement, flow adjusting ,arrangement & magnehelic
guage / PLC Control panel
A] Testing using Analog Magnehelic Gauge & B] Using PLC
Control Panel
EQUIPMENT REQUIRED:
a) Blower with motor and Volume control damper
b) Magnehelic Gauges
0 50 mmwc .. 1 No.
0 100 mmwc .. 1 No.
c) Flexible Duct
3.1 Close all Duct Opening with temporary seals
3.2 Calculate the area of Duct in Ft2
Note: The construction class of the Duct as per requirement in
Pharma industry is not more than 3. Hence Leakage class (CL) for
rectangular duct is 12. (as per Table 4.1)
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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 2 of 8
3.3 Connect the apparatus as per drawing Fig 3.1.
3.4 Connect Magnehelic gauge (0 50 mmwc) across orifice
plate.
3.5 Connect high pressure port of 0 -100 mmwc Magnehelic Gauge
in the duct and keep the low pressure port of the gauge open to
atmosphere
3.6 Adjust Blower to require Static Pressure
3.7 Calculate the Leakage factor (F) by using the relation
CL = F/P0.65 F = CL x P0.65 CL = Duct leakage class
P = Testing pressure in inches of WC.
3.8 Calculate the allowable leakage by using the following
expression
Allowable leakage = (Area of duct in Ft2 x F)/100
3.9 Note down the orifice and tube diameter.
3.10 Note down the Differential pressure reading across
Orifice.
3.11 Refer table 1.1 and find out the actual Leakage through
duct for the corresponding values of Differential pressure.
3.11.1 B] Using PLC Control Panal
3.11.1.1 Connect the Testing Blower to section of ductwork to be
tested
3.11.1.2 Start the fan and adjust the flow so as to develop the
static pressure in duct 25mm of wg or as per requirement
3.11.1.3 Check the measured leakage is within the permitted
rate.
3.11.1.4 Maintain the test for 10 - 15min and check that the
leakage rate has not increased
3.11.1.5 Record the test results/print the test results
3.11.1.6 If the leakages are above the permissible limits
carryout rectification of leaks by Tightening the duct joints
properly with nut-bolts, change the sealant
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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 3 of 8
Reseal the ducts wherever locations have been identified.
3.11.1.7 Repeat the procedure till you get the leakages within
permissible limits.
3.12 ACCEPTANCE CRITERIA:-.
a) For 2 testing Pressure leak rate should be Less than or equal
to 18.8 CFM / 100 Sqft Duct.
b) For 3 testing Pressure leak rate should be Less than or equal
to 24.5 CFM / 100 Sqft Duct.
c) For 4 testing Pressure leak rate should be Less than or equal
to 29.5 CFM / 100 Sqft Duct.
3.13 Prepare check sheet for duct leak test as per attached
format.
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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 4 of 8 Table 1.1:-
Delta P mm WG Flow Rate CFM Delta P mm WG Flow Rate CFM
1 14.56 26 72.60 2 20.49 27 73.96 3 25.03 28 75.30 4 28.84 29
76.61 5 32.20 30 77.90 6 35.23 31 79.17 7 38.01 32 80.42 8 40.60 33
81.65 9 43.03 34 82.86
10 45.32 35 84.06 11 47.50 36 85.23 12 49.58 37 86.39 13 51.58
38 87.54 14 53.50 39 88.66 15 55.35 40 89.78 16 57.14 41 90.88 17
58.87 42 91.96 18 60.56 43 93.04 19 62.19 44 94.10 20 63.79 45
95.15 21 65.34 46 96.18 22 66.86 47 97.21 23 68.34 48 98.22 24
69.79 49 99.23 25 71.21 50 100.22
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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 5 of 8
y = 14.56x0.493R = 0.998
0
20
40
60
80
100
120
0 10 20 30 40 50 60
Flow
Rat
e (C
FM)
Delta P (mm WC)
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BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 6 of 8
-
BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 7 of 8
-
BOTTOMGRASS ENGINEERING & HVAC SERVICES
HVAC Consulting , Installation & Validation Issue Date April
2013
Effective Date April 2013
Standard Operating Procedure Review Date Nil Document Title
Procedure Duct Leakage Test Rev R0
Sop No. BG/ES/HV/008/00 Page 8 of 8
4 ABBREVIATIONS
4.1 SOP Standard Operating Procedure No. Number
5 REFERENCES
5.1 SOP BGES-00-800
6 RESPONSIBILITY
6.1 Validation Department.
7 ANNEXURES
7.1 Format for Duct Leakage Test