Duc-Tester Manual
for California Title 24 Duct Testing rev 2009-01-27
Using either a Retrotec R31 or Q32 system with a Retrotec DM-2 MkII gauge
Retrotec Energy Innovations, Ltd.
Phone: 604-732-0142 Fax: 604-737-0162
[email protected]
[email protected]
www.retrotec.com
Hours: 0800-1600 PST
Manufacturing Plant: 1060 East Pole Road, Everson, WA, USA 98247
Old version showing clear tube
Retrotec Duc-Tester Model R31 & Q32 Instructions
Instructions are for pressurization testing of ducts.
1. Position the DucTester near the largest
return.
Flex duct can be left
permanently mounted to
the outlet of the fan for
Pressurization tests.
Mid range nozzle should be
installed. This Mid range
will be suitable for most
new homes. Super tight
ducts may need the Low
flow nozzle installed over
top. Leaky ducts may
require both nozzles
removed so the inlet is
Open.
Instructions for Optional depressurization testing.
Title 24 requires pressurization testing which is
blowing air into the ducts to achieve a positive test
pressure. It may be preferable to depressurize,
however in cases where the tape gets blown off by the
duct tester. Results will be very similar.
4. Attach flange to return
Attach the return flange over top of the main return
register. Alternatively, remove the air handler access
door, install cardboard to fill the opening, cut an 8
inch diameter hole in the cardboard and attach the
return flange over top of this hole. Seal around the
flange with Retrotec Grill Mask and/or tape. Ensure
there are no leaks.
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2. Turn off air handler.
Turn off the HVAC
system or adjust the
thermostat so the Airhandler cannot come on
during this test. Put
your car keys beside the
switch to remind you to
turn it back on because
you will forget.
3. Remove furnace filter
Remove the furnace filter
and ensure that the filter
open is sealed to the same
extent as it is when the
filter is in place. All doors
to the air-handler
compartment must be
closed.
To depressurize:
-install the duct on the front of the Duc-Tester fan.
-attach the flange & flex-duct to the inlet register.
-attach a green tube between the green connector on
the DM-2 and the green port on the Duc-Tester. This
additional step tube must be completed in order to offset the fact
that there is pressure in the flex duct that will affect the flow
pressure reading. Small reference ports on the outside of the fan
inlet will measure the pressure in the duct and properly
compensate the flow.
5. Attach the flex-duct
Attach the flex-duct to the register flange using the
Velcro strap. Pull on the two tabs simultaneously,
then push them flat to connect the Velcro.
Created by Colin Genge
6. Insert blue tube into Supply
and cover all supplies
Insert the blue tube into the
supply. This tube will be used to
measure the pressure that the DucTester creates in the ducts. Push
the tube into the register and seal
with Retrotec Grill Mask. Use tube
extensions as needed if registers
are far away.
7. Seal all other supply and
return grills. Any leaks will
show up as duct leaks, so do a
good job on each register,
ensuring that it is sealed to the
wall perfectly. Ensure that you
have sealed all registers,
including any air inlets that are
connected from outdoors to the
duct system.
8. Open doors or windows or hatches
between the space where the DucTester is set up and the spaces where
the ducts run. This must be done to
ensure that pressures are not built up
in one space versus the other,
thereby obscuring leaks. Ensure a
window or door is open to outdoors.
Generally, a half square foot opening
is sufficient.
9. Connect Model R31 Duc-Tester with DM-2, OR >>>
9. Connect the Model Q32 Duc-Tester with DM-2A
Similar for Models 100, 101, 102a
Plug the 120 volt cord into the Duc-Tester and the
other end into a wall outlet.
Plug the 120 volt cord into the Duc-Tester and the
other end into a wall outlet.
Plug the remote speed control into the Duc-Tester.
Plug a yellow tube to the port labeled “Ref B(Fan)”on
the Duc-Tester. This may also be labeled “Flow Pressure” on
some fans.
From the umbilical cord plug into the fan:
9 an Ethernet style plug for speed control,
9 a yellow tube to “Ref B(Fan)”
9 a green tube to “(B)”
From this end of the umbilical cord a 15 ft. blue tube
should have been inserted into a supply in Step 6.
For this Pressurization test, only one yellow tube is needed but if in doubt, connecting a yellow and green tube between the Duc-Tester
and the DM-2 is never wrong. For depressurization testing, one yellow and one green MUST be connected between the fan and Duc-Tester.
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Created by Colin Genge
For Models 100, 101, 102a and R31
For Model Q32
10. Connect the DM-2, OR >>>>>>>>>>>>>>>>>>>>
10. Connect the DM-2A
Plug the blue tube into the blue connector.
The other end
Plug in the Ethernet connector.
The other end was plugged
was inserted in the supply in Step 6.
into the fan in Step 9.
Plug yellow tube into the yellow connector labeled
“Ref B(fan)”. The other end was connected to the fan in Step 9.
end was inserted in the supply in Step 6.
For Pressurization testing, only one yellow tube is needed. For
depressurization testing a green tube must be connected between
the green “Input B (+)”port on the DM-2 and the remaining port on
the Duc-Tester.
Plug the blue tube into the blue connector.
The other
Plug yellow tube into the yellow connector labeled
“Ref B(fan)”.The other end was connected to the fan in Step 9.
For Pressurization testing, only one yellow tube is needed. For
depressurization testing a green tube must be connected between
the green “Input B (+)”port on the DM-2 and the remaining port on
the Duc-Tester.
11.1 Turn on and set up the DM-2
11.2 Set the Device
Turn on the DM-2 and press the [Mode] key until “PrA”
and “Flow” appears on the left side of the display.
The units should read “Pa” and “cfm” on the right side
of the display.
If the bottom right hand part of the window does NOT
display:
If not, download “QuickGuide-DM2MkII.pdf” from
www.retrotec.com to make changes using [Setup] key.
Charge the NiMH batteries using the power supply for 8
hours prior to first use and repeat whenever battery
indicator falls below half.
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“Duc-Tester DU200”, then press [Device] until it
appears.
For older Retrotec models 100, 101 and 102a Duc-Testers, select
“Duc-Tester DU100”. Other models can be accessed under Device
as well.
Download “QuickGuide-DM2MkII.pdf” to see how to eliminate all
other models to avoid confusion.
Created by Colin Genge
For Model R31 with DM-2 MkII
12. Create a 25 Pa pressure in the ducts, OR >>>>>
For Model Q32 with DM-2A MkII
12. Create a 25 Pa pressure in the ducts
Press the [Set Pressure] key, then [2], [5] then
[Enter]. The DM-2A will now adjust the speed to
achieve 25 Pa automatically.
Adjust the manual speed control on the DucTester until “PrA” reads 25 Pa (0.100 inches of
water column).
If a pressure of 25 Pa cannot be achieved, remove the Mid range low flow plate with the 2 inch diameter
hole in it and adjust the speed till 25 Pa is achieved. If “Flow” displays “TOO LOW!”, add the Low range 1 inch
diameter nozzle.
To speed up the test and improve accuracy, ensure that “cfm @ 25.0 Pa” is displayed to the right of the flow.
This will give you results at 25 regardless of your test pressure, meaning that you don’t have to get the test
pressure exact; within 1 Pa is perfect. The DM-2 will then display the result you would get if you achieved
exactly 25 Pa. To get this feature, press the [@] key. If 25 is not displayed, change this in [Setup];
download“QuickGuide-DM2MkII.pdf” from www.retrotec.com. When using the @ feature, “n” should be
displayed as “0.60” for duct systems. Change this in Setup if needed.
14. Record Duct Pressure and Flow
Set Time Avg to 10 Seconds. With the Duc-Tester
running at a steady speed, watch the readings for 15
seconds to ensure they are stable then record the duct
pressure and flow in cfm. If the @25 feature is used,
record the flow with “@ 25 Pa” displayed.
15. Record Flow Direction
Air being blown into ducts is pressurization and air
being sucked out of ducts is depressurization.
16. Maximum Allowable duct leakage is calculated
using the tables in the test form. Record this value.
13. Ensure the “Range Config” display matches the
range on your Duc-Tester. If not, press the [Range
Config] key until it does. All R31 and Q32 have an
Open range with no nozzles installed, a Mid range
which is a 2.5 inch nozzle and a Low range which is a
1 inch nozzle. Mid range will test all new houses but
the Open range may be needed for existing and
leakier ducts. Low range is for tight ducts.
For Title 24, calculate the maximum allowable leakage
using any of the 4 methods shown. These methods
combine several calculations into one simple
calculation to see if the ducts meet Title 24
requirements.
Pass Fail
If the maximum allowable duct leakage is greater than
the flow read off the chart, the house passes. If not,
it fails. Record the actual test pressure and flow even
if the @ pressure feature is used.
Record the flow range configuration used for the test.
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Created by Colin Genge
Duc-Test Form
to California Test Standard Title 24
Test date: …………………/200__
For:
Model 102a Duc-Tester System with DU-102 fan and DM-2 digital gauge Serial # ………………… , or
Model R31 Duc-Tester System with DU-210 fan and DM-2 digital gauge Serial # ………………… , or
Model Q32 Duc-Tester System with DU-220 automatic fan and DM-2A automatic digital gauge Serial # …………………
Address: ................................................. Contact: .............................. Phone: .......................
.........................................................
Technician: .............................. ........... ........... ......
The Duc-Tester measures the total leakage of a duct system by pressurizing all ducts to 25 Pascals
with the air-handler off and the registers taped over.
Step
…√
Detailed Description of the Step
1
Position Duc-Tester near return
Ensure the flex will reach the return grill
2
Turn Air-handler off
Put your car keys beside the switch
3
Remove the furnace filter
Cover filter opening
4
Attach flange + flex to return register
… or __access door in the air handler
6
Insert blue tube in a supply register
7
Seal all other registers
8
Open doors or windows
9
Connect the Duc-Tester
10
Connect the DM-2
11
Turn on and set up the DM-2
12
Create a 25 Pa pressure in the ducts
13
Range Configuration
14
Record Flow and Pressure
____ cfm, ___ Pa with NO @ pressure displayed.
Record Flow with @ 25 Pa displayed.
Record n and TimeAvg displayed.
____ cfm, __ @ 25 feature used.
___ pressurize with flow into ducts, __depressurize
16
Record Flow Direction
Maximum Allowable duct leakage per
page 7 is:
17
Remove tape
18
Turn HVAC equipment back ON
Remove tape from registers.
Re-install the furnace filter and turn all HVAC equipment
back ON
15
do NOT seal to the wall or ceiling.
__ yellow tube, __ power cord, __ speed control,
__green tube.
__ Low 1” nozzle, __Mid 2” nozzle, __Open inlet.
___ n and ___ seconds of Time Average displayed.
____ cfm, ___ Pass,
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___ Fail.
Created by Colin Genge
New duct systems
must leak less than 6% of the air handler’s flow.
The Maximum allowable duct tester measurement based on 4 different ways of calculating air handler flow is:
TONNAGE ___ X 24 = _____ cfm
1. For A/C systems multiply the Tonnage X 24 cfm.
Assumes 400 cfm per Ton with maximum allowable leakage of 6% = 24 cfm per Ton.
E.g. a 5 Ton system must have 5 X 24 = 120 cfm of leakage or less at a 25 Pa test pressure in the supplies.
BTU _________ /1000 X 1.302 = ____cfm
2. For Heating systems divide the BTU /1000 X 1.302 cfm.
Assumes 21.7 cfm per 1000 BTU capacity with maximum allowable leakage of 6% =
1.302 cfm per 1000 BTU.
E.g. a 100,000 BTU furnace must have 100,000 / 1000 X 1.302 = 132 cfm of leakage or less.
3. For climates 8 through 15 divide the Floor Area by 1000 X 42 cfm.
Floor Area ______ / 1000 X 42 = ____cfm
For climate zones 7 and 16 divide the Floor Area by 1000 X 30 cfm
Floor Area ______ / 1000 X 30 = ____cfm
E.g. a 3,000 sq. ft. home must have 3,000 / 1000 X 42 = 126 cfm or less for climates 8 through 15
E.g. a 3,000 sq. ft. home must have 3,000 / 1000 X 30 = 90 cfm or less for climate zones 7 and 16.
4. Measure the fan flow divided by 100 X 6.
Measured fan flow ______ / 100 X 6 = ____cfm
E.g. an air-handler blower flow of 2000 cfm must have 2000 / 100 X 6 = 120 cfm of leakage or less.
Existing duct systems
must leak less than 15% of the air handler’s flow.
The Maximum allowable duct tester measurement based on 4 different ways of calculating air handler flow is:
1. For A/C systems multiply the Tonnage X 60 cfm.
TONNAGE ___ X 60 = _____ cfm
Assumes 400 cfm per Ton with maximum allowable leakage of 15% = 60 cfm per Ton.
E.g. a 5 Ton system must have 5 X 60 = 300 cfm of leakage or less at a 25 Pa test pressure in the supplies.
BTU _________ /1000 X 3.255 = ____cfm
2. For Heating systems divide the BTU /1000 X 3.255 cfm.
Assumes 21.7 cfm per 1000 BTU capacity with maximum allowable leakage of 15% = 1.302
cfm per 1000 BTU.
E.g. a 100,000 BTU furnace must have 100,000 / 1000 X 3.255 = 326 cfm of leakage or less.
3. For climates 8 through 15 divide the Floor Area by 1000 X 42 cfm.
For climate zones 7 and 16 divide the Floor Area by 1000 X 30 cfm
Floor Area ______ / 1000 X 105 = ____cfm
Floor Area ______ / 1000 X 75 = ____cfm
E.g. a 3,000 sq. ft. home must have 3,000 / 1000 X 105 = 315 cfm or less for climates 8 through 15
E.g. a 3,000 sq. ft. home must have 3,000 / 1000 X 75 = 225 cfm or less for climate zones 7 and 16.
4. Measure the fan flow divided by 100 X 15.
Measured fan flow ______ / 100 X 15 = ____cfm
E.g. an air-handler blower flow of 2000 cfm must have 2000 / 100 X 15 = 300 cfm of leakage or less.
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Created by Colin Genge