These operating instructions are for ORIFLOW model PANTHER air leakage testers.
Take pride in knowing that you have purchased the best air leakage tester on the
market. It is no secret that Oriflow manufactures the highest quality testers, and has
unparalleled customer service and technical support.
The orifice plates available for your duct leakage tester are constructed from lasercut 0.125-inch stainless steel and do not require recalibration for 10 years. Note the
authority having jurisdiction may override this requirement, and if so, Oriflow has very
reasonable rates for calibrating orifice plates manufactured by Oriflow.
Safety Precautions
Before operating your tester, read the following safety precautions:
DO NOT operate the tester in the rain,
DO NOT operate the tester while it is near or in water,
DO NOT operate the tester with a damaged electrical cord or plug,
DO NOT remove the inlet safety screen,
DO NOT touch the blower wheel when the unit is plugged in,
DO NOT look into the discharge end of the tester when the unit is plugged in,
DO NOT use the tester as a ladder or step stool,
DO NOT allow children near the tester,
DO use an extension cord of the proper gauge (see Table 2),
DO use the proper voltage and line frequency listed on the motor nameplate,
DO lock the caster when the tester is positioned horizontally,
DO use the tester on level ground,
DO secure the tester when transporting it,
DO wear proper hearing protection, safety glasses and work gloves,
DO seek assistance when lifting the tester (e.g., loading onto truck, going up
System Preparation
Cap off all ends of system using clear plastic and duct tape or sheetmetal duct end
caps. Make sure you test the part of the duct system that leakage testing is required.
Usually, this is from the system fan up to, but not including, the VAV boxes (terminal
units). Refer to the engineer's specifications and all applicable codes and test
standards.
Power Requirements
Do you have an adequate power supply for your tester (see Table 1)?
Table 1 – Tester Amp Draw
Tester
Model
Panther
* - The only flow control option for the Panther is the inlet slide gate. If a
speed controller is desired, consider the Rhino model.
Voltage
115 Inlet Slide Gate 31
230 Inlet Slide Gate 16
Flow Control
Option*
Full Load
Amps
Extension Cord Requirements
If you need an extension cord, is it the proper gauge? See Table 2 below for
extension cord requirements.
Table 2 – Required Extension Cord Wire Gauge
Tester Model Voltage
115
Panther
230 up to 100 12
Extension Cord Length
(feet)
up to 50 8
51 to 100 6
Wire Gauge
Flex-Duct Length
Make sure you have enough flexible-duct with your tester for the job. Each tester
includes 12.5 feet, which is enough for most applications. Extra lengths of flexibleduct are available at www.oriflow.com/Products
To determine the maximum allowable leakage for the project, use ORIFLOW’s free online programs to make these calculations (www.oriflow.com/Technical).
Calculations are done for either of the two typical specifications: percentage of
system flow, or leakage class. If the specification uses leakage class, you will need
to calculate the total duct system surface area. Oriflow has a free Adobe form
available to our customers that will calculate duct surface area given the duct shape,
dimensions and length.
Determining Which Orifice Plate to Use
After determining the allowable leakage at the system test pressure, refer to the
following tables for the capacities of each orifice plate available for the PANTHER
model tester. Make sure you have an orifice plate that can measure the maximum
allowable leakage. The proper plate is the one where the maximum allowable
leakage falls between the minimum and maximum leakage at the system static
pressure. For example, if you are testing a system at 4 in.wg. pressure and the
maximum allowable leakage is 600 cfm, you will need a 4-inch orifice since the 4inch plate can test up to 740 cfm at a test pressure of 4 in.wg.
It is a good idea to have the next larger orifice plate size since it is common for duct
systems to leak more than the maximum allowable. Smaller diameter plates are use
when leakage is relatively low.
Table 3 – Tester Capacity using the 1-inch Orifice Plate
System Static
Pressure
(in.wg.)
2
4
6
8 5 30
10
12
Minimum
Flow Rate*
(cfm)
5 45
5 40
5 35
5 25
5 15
Table 4 – Tester Capacity using the 2-inch Orifice Plate
Install Orifice Plate
The orifice plate that was determined from the previous section should now be
installed. Install the orifice plate with the serial number facing upwards so the
corresponding calibration certificate may be referenced after installation. Refer to
Connect Flex-Duct to Duct System
Find a convenient location in the duct system where the tester has easy access.
Make sure that the connection where you connect the flexible duct is a sturdy, sealed
tight connection. You don’t want to create a leaky connection where the tester is
supplying air into the system.
System Test Pressure Connection
So that you can monitor the system static pressure, you need to drill a hole at least 3
feet away from the flex-duct connection. Drill a 5/16-inch diameter hole and insert
the pressure tubing from the “DUCT SYSTEM” gauge so that 6 to 12 inches of tubing
is inside the duct system. Using putty or duct tape, seal the connection. If your
pressure tubing has a plastic static pressure tap at the end of the pressure tubing,
insert the tap in the hole and seal it to the duct wall using duct tape. See Figure 4
below.
Figure 7 - Static Pressure Tubing Connection
See Figure 8 showing the test setup for SUPPLY system testing. Refer to Figure 9
for the test setup required to measure air leakage of a RETURN/EXHAUST system.
DUCT SYSTEM pressure tubing
inserted into duct system
Zeroing Pressure Gauges
Before you run the tester, make sure both gauges have been zeroed.
Zeroing Analog Gauges
Using a very small screwdriver, turn the zero-adjustment screw on the gauge
until the needle is aligned with the zero reading. Turning the screw clockwise
increases the pressure reading; turning it counterclockwise, decreases the
reading. See Figure 10.
Figure 10 – Zeroing Analog Gauges
(zero BOTH gauges before testing)
Zeroing Digital Gauges
Use the following steps to zero each digital gauge:
1. Press MENU button once.
2. Press
3. Press
4. Press
5. Press
6. Press MENU button two times to get back to the pressure reading.
7. Pressure should be reading zero or within +/- 0.02 in.wg. If not, repeat
steps.
E button once to go into auto-zero mode
E button again and AUTO will be blinking on screen
E button a third time to complete the zeroing process.
11
Avoid Over Pressurization
Prior to starting the blower, shut the inlet slide gate completely so that when the
blower is turned on, it will not over pressurize the duct system.
Figure 12 – Avoid Over-Pressurizing by Minimizing Air Delivery upon Startup
Obtaining System Test Pressure
Turn the blower on and slowly open the inlet slide to obtain system test pressure.
Regardless of tester model used, pay attention to the “DUCT SYSTEM” gauge while
increasing airflow. When you have reached the required system static pressure,
tighten the set-screw on the inlet damper (or stop rotating the speed control knob).
Determining the Leakage Rate
Now that you have obtained the system test pressure and have the inlet damper
locked in position, note the pressure reading of the ORIFICE TUBE gauge (Figure
15). Refer to your calibration certificate to determine the leakage rate that
corresponds to the gauge reading. An example of a calibration certificate is shown in
Figure 16; it is for informational purposes only and used in the example shown on the
next page. Always refer to the calibration certificate that came with your
SAMPLE CALIBRATION CERTIFICATE TABLE FOR EXAMPLE ONLY
USE YOUR CERTIFICATE
Figure 16 – Tables from a Sample Calibration Certificate. Every calibration chart has an equation located
below the table (not shown here)
Example (refer to Figure 16)
For an ORIFICE TUBE gauge reading of 1.15 in.wg., the leakage rate
appears to be approximately 143 cfm.
For an exact value, use the equation that comes with every calibration
certificate. For the example shown in Figure 16:
Leakage = 133.6 x ,
where the value of “133.6” is a constant and will be specific to the orifice
plate used (every plate has its own value; yours will be different).
Using a calculator, take the square root of the gauge reading first, and then
multiply by the constant for your orifice plate (for this example, the constant
is "133.6"). The exact leakage is 133.6 x (square root of 1.15) = 143.3 cfm.
In most cases, reporting the leakage as 143 cfm is acceptable.
Zero reading on “DUCT SYSTEM” gauge
If the gauge reading is zero, refer to the table below to fix this problem. Perform
troubleshooting steps in the order shown in the Table 7 below.
Table 7 –Troubleshooting steps when “DUCT SYSTEM” gauge is zero
Step Scenario What to do
1
2
3
4
Inlet damper was left shut,
cutting off air to the system.
Pressure tubing connected
to gauge incorrectly
Plugged fitting or
malfunctioning gauge.
System is leaking
too much air.
Open inlet damper slowly.
Look at the P1 and P2 stickers that are located on the
orifice tube and gauges. Make sure tubing from P1 tap
matches the P1 tap on the “ORIFICE TUBE” gauge.
Gently blow through other end of pressure tubing from
“DUCT SYSTEM” gauge, and watch needle increase
pressure reading.
Check for these other sources of leakage:
Rectangular duct joints (check and seal corners),
Fire or smoke dampers,
Duct joints (pay particular attention to flex-duct
joints if they are part of the leak test),
VAV boxes (pay particular attention to parallel box
Zero reading on “ORIFICE TUBE” gauge
If the gauge reading is zero, refer to the table below to fix this problem. Perform
troubleshooting steps in the order shown in Table 8 below.
Table 8 –Troubleshooting steps when “ORIFICE TUBE” gauge is zero
Step Scenario What to do
1
2 Plugged pressure taps.
3
4
4
5 Malfunctioning gauge.
6 Not sure
Inlet damper was left shut,
cutting off air to the system.
Orifice plate too large for
application.
System is leaking very little
air.
Pressure tubing connected
incorrectly.
Open inlet damper slowly.
Remove pressure tubing from “ORIFICE TUBE” gauge, and
blow through each end to make sure the pressure taps on
the orifice tube are clear.
If you are using a 4-inch ID orifice plate, and the system is
leaking 40 cfm, you probably won’t even notice the gauge
needle moving. This can happen to other orifice plates too.
You need to purchase an orifice plate with a smaller bore
diameter so that a small amount of airflow/leakage will
result in a bigger pressure drop.
You’ll know if this is true if the fan inlet is almost shut. Not
likely unless system is small. Fix is to use plate with
smaller bore.
Look at the P1 and P2 stickers that are located on the
orifice tube and gauges. Make sure they match.
Remove the clear pressure tubing from the lower pressure
tap on the orifice tube and blow through the end of the
tubing. The needle should move in response. If not, the
gauge is faulty.
The best way to make sure that your tester is working
properly is to disconnect the flex duct from the system and
turn the blower on, and slowly open the inlet damper. If you
feel a lot of air coming out of the tube end, you should see
a pressure reading on the gauge “ORIFICE TUBE”.
Can’t obtain system test pressure
This happens when the system is leaking too much air. Make sure all outlets are
sealed. Check corners of rectangular duct for excessive leakage. Inspect all duct
and fitting joints for leakage. Make sure you seal all suspect joints and allow to cure
24 to 48 hours. Always refer to duct sealant manufacturer’s instructions.
Check for these other sources of leakage:
Rectangular duct joints (check and seal corners),
Fire or smoke dampers,
Duct joints (pay particular attention to flex-duct joints if they are part of the
leak test),
VAV boxes (pay particular attention to parallel box back draft dampers),
Built-up air handlers,
Plenums,
Uncured duct sealant blow-thru (follow manufacturer instructions for cure
time),
Improperly sealed or un-sealed joints,
Hot water coils and electric heaters,
Open duct end that was supposed to be sealed/capped-off for the leak test.
A non-toxic smoke machine is an excellent tool for locating significant sources of
leakage. Call ORIFLOW at 727-400-4881 or online at www.oriflow.com
information.
“ORIFICE TUBE” gauge reading maxed out
Scenario 1: The system is leaking too much air. Make sure all outlets are
sealed. Check corners of rectangular duct for excessive leakage. Inspect all
duct and fitting joints for leakage. Make sure you seal all suspect joints and
allow curing time of 24 to 48 hours. Always refer to duct sealant
manufacturer’s instructions.
Scenario 2: orifice plate bore could be too small, causing a high pressure
drop at low to moderate flows. You need an orifice plate with a larger bore.
ORIFLOW LLC
www.oriflow.com
2125 Range Rd., Unit B
Clearwater, Florida 33765
727-400-4881 (phone) 8am to 5pm PST
877-420-7091 (fax)
sales@oriflow.com
engineering@oriflow.com