TEC MINNEAPOLIS BLOWER DOOR 3 User manual

Minneapolis Blower Door™
Operation Manual
for
Model 3 and Model 4 Systems

Minneapolis Blower Door™
Operation Manual
for
Model 3 and Model 4 Systems
The Energy Conservatory
2801 21st Ave. S., Suite 160
Minneapolis, MN 55407
[phone] (Ph)
[phone] (Fax)
www.energyconservatory.com
email: [e-mail]
Minneapolis Blower Door, TECTITE, Duct Mask and Automated Performance Testing (APT) System are
trademarks of The Energy Conservatory, Inc. Minneapolis Duct Blaster and TrueFlow Air Handler Flow Meter
are registered trademarks of The Energy Conservatory, Inc.
Windows and Microsoft Word are registered trademarks of Microsoft Corporation.

Manual Edition: August 2012.
© 2012 by The Energy Conservatory. All rights reserved.
ENERGY CONSERVATORY WARRANTY
EXPRESS LIMITED WARRANTY:
Seller warrants that this product, under normal use and service as described in the operator’s manual, shall be free from defects in
workmanship and material for a period of 24 months, or such shorter length of time as may be specified in the operator’s manual, from the
date of shipment to the Customer.
LIMITATION OF WARRANTY AND LIABILITY:
This limited warranty set forth above is subject to the following exclusions:
a) With respect to any repair services rendered, Seller warrants that the parts repaired or replaced will be free from defects in
workmanship and material, under normal use, for a period of 90 days from the date of shipment to the Purchaser.
b) Seller does not provide any warranty on finished goods manufactured by others. Only the original manufacturer’s warranty applies.
c) Unless specifically authorized in a separate writing, Seller makes no warranty with respect to, and shall have no liability in
connection with, any goods which are incorporated into other products or equipment by the Purchaser.
d) All products returned under warranty shall be at the Purchaser’s risk of loss. The Purchaser is responsible for all shipping charges
to return the product to The Energy Conservatory. The Energy Conservatory will be responsible for return standard ground shipping
charges. The Customer may request and pay for the added cost of expedited return shipping.
The foregoing warranty is in lieu of all other warranties and is subject to the conditions and limitations stated herein. No other express or
implied warranty IS PROVIDED, AND THE SELLER DISCLAIMS ANY IMPLIED WARRANTY OF FITNESS for particular purpose or
merchantability.
The exclusive remedy of the purchaser FOR ANY BREACH OF WARRANTY shall be the return of the product to the factory or designated
location for repair or replacement, or, at the option of The Energy Conservatory, refund of the purchase price.
The Energy Conservatory’s maximum liability for any and all losses, injuries or damages (regardless of whether such claims are based on
contract, negligence, strict liability or other tort) shall be the purchase price paid for the products. In no event shall the Seller be liable for any
special, incidental or consequential damages. The Energy Conservatory shall not be responsible for installation, dismantling, reassembly or
reinstallation costs or charges. No action, regardless of form, may be brought against the Seller more than one year after the cause of action
has accrued.
The Customer is deemed to have accepted the terms of this Limitation of Warranty and Liability, which contains the complete and exclusive
limited warranty of the Seller. This Limitation of Warranty and Liability may not be amended or modified, nor may any of its terms be waived
except by a writing signed by an authorized representative of the Seller.
TO ARRANGE A REPAIR: Please call The Energy Conservatory at 612-827-1117 before sending any product back for repair or to inquire
about warranty coverage. All products returned for repair should include a return shipping address, name and phone number of a contact
person concerning this repair, and the purchase date of the equipment.

Table of Contents
SAFETY INFORMATION 1
CHAPTER 1 INTRODUCTION 2
1.1 What is a Blower Door? 2
1.2 Air Leakage Basics 3
1.2.a Stack Effect: 4
1.2.b Wind Pressure: 4
1.2.c Point Source Exhaust or SupplyDevices: 4
1.2.d Duct Leakage to the Outside: 4
1.2.e Door Closure Coupled with Forced Air Duct Systems: 4
1.3 Common Air Leakage Sites 4
CHAPTER 2 SYSTEM COMPONENTS 7
2.1 Blower Door Fan 7
2.1.a Determining Fan Flow and Using the Flow Rings: 8
2.2 Test Instrumentation (Pressure and Fan Flow Gauges) 9
2.2.a DG-700 and DG-3 Digital Pressure Gauges: 9
2.2.b Automated Performance Testing System™: 10
2.3 Fan Speed Controllers 11
2.4 Adjustable Aluminum Door Frame 11
2.5 TECTITE Blower Door Test Software 12
2.5.a TECTITE Features: 12
CHAPTER 3 INSTALLING THE BLOWER DOOR FOR DEPRESSURIZATION
TESTING 13
3.1 Door Frame and Panel Installation 13
3.1.a Where To Install The Door Frame? 13
3.1.b Installing the Aluminum Frame: 13
3.2 Installing the Outside Building Pressure Tubing 14
3.3 Installing the Blower Door Fan 15
3.4 Attaching the Gauge Mounting Board 15
3.5 Gauge Tubing Connections for Depressurization Testing 16
3.5.a DG-700 Gauge: 16
3.5.b DG-3 Gauge: 16
3.5.c APT System: 17
3.6 Electrical and Tubing Connections to the Fan 17
3.6.a Electrical Connections: 17
3.6.b Connecting Tubing to the Model 3 Fan: 18
3.6.c Connecting Tubing to the Model 4 Fan: 18
3.7 Fan Control Cable for Cruise Control 18
CHAPTER 4 SETTING UP THE BUILDING FOR TESTING 19
4.1 Adjustable Openings 19
4.2 Combustion Appliance/Exhaust Devices 19
4.3 Testing For New Construction 20

CHAPTER 5 CONDUCTING A BLOWER DOOR DEPRESSURIZATION TEST 21
5.1 Choosing a Test Procedure 21
5.2 Depressurization Test Procedures Using the DG-700 21
5.3 Depressurization Test Procedures Using the DG-3 24
5.4 Using the Can’t Reach 50 Factors (One-Point Tests) 27
5.4.a Potential Errors In One-Point CFM50 Estimate from Using the CRF Factors: 28
5.5 Unable to Reach a Target Building Pressure During a Multi-Point Test? 29
5.6 Testing in Windy Weather 29
5.7 Before Leaving the Building 29
CHAPTER 6 BASIC TEST RESULTS 30
6.1 Basic Airtightness Test Results 30
6.1.a Air Leakage at 50 Pascals: 30
6.1.b Normalizing Air Leakage for the Size of the House: 31
6.2 Optional Correction for Air Density 32
6.3 Additional Test Result Options (requires use of TECTITE software) 33
6.3.a Leakage Areas: 33
6.3.b Estimated Natural Infiltration Rates: 33
6.3.c Mechanical Ventilation Guideline: 34
6.3.d Estimated Cost of Air Leakage: 35
CHAPTER 7 PRESSURIZATION TESTING 36
7.1 Gauge Set-Up For Pressurization Measurements 36
7.1.a DG-700 and DG-3 Gauges: 36
7.1.b APT System: 37
7.2 Fan Set-Up For Pressurization Measurements 38
7.3 Optional Correction for Air Density 38
CHAPTER 8 FINDING AIR LEAKS 39
8.1 Using Your Hand 39
8.2 Using a Chemical Smoke Puffer 39
8.3 Using an Infrared Camera 39
8.4 Diagnosing Series Leakage Paths 40
CHAPTER 9 TESTING FOR DUCT LEAKAGE AND PRESSURE
IMBALANCES 41
9.1 Duct Leakage Basics 41
9.1.a Why Is Duct Leakage Important? 41
9.1.b Where Does Duct Leakage Occur? 41
9.1.c How Much Can Energy Bills Be Reduced By Sealing Duct Leaks? 42
9.1.d Duct Leakage to the Outside: 42
9.1.e Duct Leakage to the Inside: 43
9.2 Finding Duct Leaks to the Outside 43
9.2.a Smoke Test: 43
9.2.b Pressure Pan: 43
9.3 Estimating Duct Leakage to the Outside With a Blower Door 44
9.3.a Modified Blower Door Subtraction: 44

9.3.b Flow Hood Method: (Requires use of calibrated flow capture hood) 46
9.4 Unconditioned Spaces Containing Ductwork 46
9.5 Testing for Pressure Imbalances Caused By Forced Air System Flows 47
9.5.a Dominant Duct Leak Test: 47
9.5.b Master Suite Door Closure: 48
9.5.c All Interior Doors Closed: 48
9.5.d Room to Room Pressures: 49
9.6 Other Important Test Procedures 49
9.6 a Total System Air Flow: 49
9.6.b System Charge: 49
9.6.c Airflow Balancing: 49
CHAPTER 10 COMBUSTION SAFETY TEST PROCEDURE 50
10.1 Overview 50
10.2 Test Procedures 51
10.2.a Measure Ambient CO Level in Building: 52
10.2.b Survey of Combustion Appliances: 52
10.2.c Survey of Exhaust Fans: 52
10.2.d Measure Worst Case Fan Depressurization: 52
10.2.e Spillage Test (natural draft and induced draft appliances): 54
10.2.f Carbon Monoxide Test: 55
10.2.g Draft Test (natural draft appliances): 55
10.2.h Heat Exchanger Integrity Test (Forced Air Only): 55
APPENDIX A CALIBRATION AND MAINTENANCE 57
A.1 Fan Calibration Parameters (Updated January 2007) 57
Model 3 (110V) Calibration Parameters: 57
Model 3 (230V) Calibration Parameters: 57
Model 4 (230V) Calibration Parameters: 57
A.2 Issues Affecting Fan Calibration 58
A.2.a Fan Sensor and Motor Position: 58
A.2.b Upstream Air Flow Conditions: 60
A.2.c Operating Under High Backpressure Conditions: 60
A.3 Blower Door Fan Maintenance and Safety 61
A.3.a Maintenance Checks: 61
A.3.b General Operational Notes and Tips: 61
A.3.c Replacing the Model 4 Controller’s Internal Fuse: 61
A.4 Calibration and Maintenance of Digital Pressure Gauges 63
A.4.a Digital Gauge Calibration: 63
A.4.b Digital Gauge Maintenance: 64
A.5 Checking for Leaky Tubing 64
APPENDIX B FLOW CONVERSION TABLES 65
Model 3 (110V) 65
Model 3 (230V) 67
Model 4 (230V) 69

APPENDIX C USING FLOW RINGS C, D AND E 71
C.1 Using Ring C 71
C.1.a Installation: 71
C.1.b Calibration Parameters for Ring C (Updated January 2007): 71
C.2 Using Rings D and E 71
C.2.a Installation: 71
C.2.b Measuring Fan Flow with Rings D and E: 72
C.2.c Calibration Parameters for Rings D and E (Updated January 2007): 72
APPENDIX D SAMPLE TEST FORMS 74
APPENDIX E HOME ENERGY ARTICLE * 77
APPENDIX F CALCULATING A DESIGN AIR INFILTRATION RATE 83
APPENDIX G REFERENCES 85
APPENDIX H AIR DENSITY CORRECTION FACTORS 86
H.1 Air Density Correction Factors for Depressurization Testing 86
H.2 Air Density Correction Factors for Pressurization Testing 87
APPENDIX I CRUISE CONTROL WITH THE DG-700 GAUGE 88
APPENDIX J BLOWER DOOR SYSTEM SPECIFICATIONS 90

Safety Information
Safety Information
The Blower Door fan should only be connected to a properly installed and tested power supply. In
case of emergencies, disconnect the power cord from the AC power mains outlet. During
installation, use the nearest readily accessible power outlet and keep all objects away from
interfering with access to the outlet.
•Disconnect the power plug from the Blower Door fan receptacle before examining or making any
adjustments to the fan motor, blades or electrical components.
•The Blower Door Fan is a very powerful and potentially dangerous piece of equipment if not used and
maintained properly. Carefully examine the fan before each use. If the fan housing, fan guards, blade,
controller or cords become damaged, do not operate the fan until repairs have been made. Repairs should
only be made by qualified repair personnel.
•If you notice any unusual noises or vibrations, stop and unplug the fan. If you can’t find the source of the
problem, contact the manufacturer/distributor.
•Keep people, animals and objects away from the Blower Door fan when it is operating.
•Press the power plug firmly into the power receptacle on the Blower Door fan, and the AC power mains
outlet. Failure to do so can cause overheating of the power cord and possible damage.
•Do not use ungrounded outlets or adapter plugs. Never remove or modify the grounding prong. Use only
approved and inspected electrical wiring and connections.
•Do not operate the Blower Door fan if the motor, controller or any of the electrical connections are wet.
•For long-term operation, such as maintaining building pressure while air-sealing, use a flow ring whenever
possible to ensure proper cooling of the BlowerDoor fan motor. This will minimize the heating of the fan
and is important in warmer weather.
•Do not reverse the Blower Door fan (if the fan has a flow direction switch) while the blades are turning.
•The motor is thermally protected and if you experience a motor shut down, be sure to turn off the fan speed
controller so that the fan does not restart unexpectantly after the motor cools down.
•The operator should wear hearing protection when in close proximity to the fan operating at high speed.
•Adjust all combustion appliances so they do not turn on during the test. If combustion appliances turn on
during a depressurization test, it is possible for flames to be sucked out of the combustion air inlet (flame
rollout). This is a fire hazard and can possibly result in high CO levels.
•If there are attached spaces (e.g. townhouses) that could contain a vented combustion appliance, either
adjust those appliances to prevent them from turning on during the test, or be sure that the attached spaces
are not depressurized or pressurized when the Blower Door is operating.
•Be sure that fires in fireplaces and woodstoves are completely out before conducting a test. Take
precautions to prevent ashes from being sucked into the building during the test. In most cases it will be
necessary to either tape doors shut, clean out the ashes, and/or cover the ashes with newspaper.
•Be sure you have returned the building to its original condition before leaving. This includes turning the
thermostat and water heater temperature controls to their original setting. Always check to see that furnace,
water heater and gas fireplace pilot lights have not been blown out during the Blower Door test - re-light
them if necessary. Remove any temporary seals from fireplaces or other openings sealed during the test.
•If combustion safety problems are found, tenants and building owners should be notified immediately and
steps taken to correct the problem including notifying a professional heating contractor if basic remedial
actions are not available. Remember, the presence of elevated levels of carbon monoxide in ambient
building air or in combustion products is a potentially life threatening situation. Air sealing work should not
be undertaken until existing combustion safety problems are resolved, or unless air sealing is itself being
used as a remedial action.
1

Chapter 1 Introduction
Chapter 1 Introduction
1.1 What is a Blower Door?
The Blower Door is a diagnostic tool designed to measure the airtightness of buildings and to help locate air
leakage sites. Building airtightness measurements are used for a variety of purposes including:
•Documenting the construction airtightness of buildings.
•Estimating natural infiltration rates in houses.
•Measuring and documenting the effectiveness of airsealing activities.
•Measuring duct leakage in forced air distribution systems.
The Blower Door consists of a powerful, calibrated fan that is temporarily sealed into an exterior doorway. The
fan blows air into or out of the building to create a slight pressure difference between inside and outside. This
pressure difference forces air through all holes and penetrations in the exterior envelope. By simultaneously
measuring the air flow through the fan and its effect on the air pressure in the building, the Blower Door system
measures the airtightness of the entire building envelope. The tighter the building (e.g. fewer holes), the less air
you need from the Blower Door fan to create a change in building pressure.
Figure 1: Blower Door Depressurization Test
2

Chapter 1 Introduction
A typical Blower Door test will include a series of fan flow measurements at a variety of building pressures
ranging from 60 Pascals to 15 Pascals (one Pascal (Pa) equals approximately 0.004 inches of water column).
Tests are conducted at these relatively high pressures to mitigate the effects of wind and stack effect pressures
on the test results. Sometimes a simple “one-point” test is conducted where the building is tested at a single
pressure (typically 50 Pascals). This is done when a quick assessment of airtightness is needed, and there is no
need to calculate leakage areas (i.e. estimate the cumulative size of the hole in the building envelope).
Figure 2: Graph of Blower Door Test Data
It takes about 20 minutes to set-up a Blower Door, conduct a test, and document the airtightness of a building. In
addition to assessing the overall airtightness level of the building envelope, the Blower Door can be used to
estimate the amount of leakage between the conditioned space of the building and attached structural
components such as garages, attics and crawlspaces. It can also be used to estimate the amount of outside
leakage in forced air duct systems. And because the Blower Door forces air through all holes and penetrations
that are connected to outside, these problem spots are easier to find using chemical smoke, an infrared camera or
simply feeling with your hand. The airtightness measurement can also help you assess the potential for
backdrafting of natural draft combustion appliances by exhaust fans and other mechanical devices, and help
determine the need for mechanical ventilation in the house.
1.2 Air Leakage Basics
To properly utilize the diagnostic capabilities of your Blower Door, it is important to understand the basic
dynamics of air leakage in buildings. For air leakage (infiltration or exfiltration) to occur, there must be both a
hole or crack, and a driving force (pressure difference) to push the air through the hole. The five most common
driving forces which operate in buildings are:
Pressure difference between inside
and outside (Building Pressure)
Flow through the
Blower Door fan
(Building
Leakage)
3

Chapter 1 Introduction
1.2.a Stack Effect:
Stack effect is the tendency for warm buoyant air to rise and leak out the top of the building and be replaced by
colder outside air entering the bottom of the building (note: when outside air is warmer than inside air, this
process is reversed). In winter, the stack effect creates a small positive pressure at the top of the building and
small negative pressures at the bottom of the building. Stack effect pressures are a function of the temperature
difference between inside and outside, the height of the building, and are strongest in the winter and very weak
in the summer. Stack induced air leakage accounts for the largest portion of infiltration in most buildings.
1.2.b Wind Pressure:
Wind blowing on a building will cause outside air to enter on the windward side of the building, and building air
to leak out on the leeward side.. At exposed sites in windy climates, wind pressure can be a major driving force
for air leakage.
1.2.c Point Source Exhaust or Supply Devices:
Chimneys for combustion appliances and exhaust fans (e.g. kitchen and bath fans) push air out of the building
when they are operating. Air leaving the building from these devices causes a negative pressure in the building
which draws outside air into holes and cracks in the building envelope. Supply fans (e.g. positive pressure
ventilation fan) deliver air into the building creating a positive pressure which pushes inside air out of the
building through holes and cracks in the building envelope. (The interaction of ventilation fans on building air
leakage and pressures is discussed in Chapter 10)
1.2.d Duct Leakage to the Outside:
Leaks in forced air duct systems (to the outside) create pressures which increase air leakage in buildings. Leaks
in supply ducts act like exhaust fans causing negative building pressures. Leaks in return ducts act like supply
fans creating positive pressures in buildings. (Duct leakage and duct leakage diagnostics are discussed in more
detail in Chapter 9).
1.2.e Door Closure Coupled with Forced Air Duct Systems:
Research has shown that in buildings with forced air duct systems, imbalances between supply and return ducts
can dramatically increase air leakage. For example, a study conducted in Florida showed that infiltration rates in
many houses were doubled whenever the HVAC system fan was operating due to pressures caused by door
closure. In the Florida houses, closing of bedroom doors created large duct imbalances by effectively cutting off
the bedroom supply registers from the central return registers located in the main part of the house. (Duct
leakage and duct leakage diagnostics are discussed in more detail in Chapter 9)
1.3 Common Air Leakage Sites
Common air leakage sites are shown in Figure 3 below. Notice how as warm air rises due to the stack effect, it
tends to escape through cracks and holes near the top of the building. This escaping air causes a slight negative
pressure at the bottom of the building which pulls in cold air through holes in the lower level. Air sealing
activities should usually begin at the top of the building because this is where the largest positive pressures exist
and where many of the largest leakage sites (and potential condensation problems) can be found.
4

Chapter 1 Introduction
The next most important location of leaks is in the lowest part of the building. The bottom of the building is
subject to the largest negative pressures, which induces cold air infiltration. Importantly, if spillage prone natural
draft combustion appliances are present, do not seal lower level building leaks unless you have first addressed
leaks in the attic or top part of the building. Sealing only lower level leakage areas while leaving large high level
leaks could create large enough negative pressures to cause combustion appliance backdrafting.
Figure 3: Common Air Leakage Sites
In addition to these common leakage sites, there can also be large leakage paths associated with hidden
construction details such as attached porches, cantilevered floors and overhangs. Figures 4 - 6 show a number
of potentially important leakage paths which are often overlooked by crews using traditional weatherization
techniques. Use of densely blown cellulose insulation or other barrier-type air sealing techniques at these key
junctures often result in dramatic air leakage reductions.
Figure 4: Hidden Construction Details
5

Chapter 1 Introduction
Figure 5: Leak from Attached Porch Figure 6: Common Kneewall Leak
Forced air system ductwork can also be a major air leakage site. Even small leaks in ductwork can result in
significant air leakage due to the high pressures found in ducts whenever the heating or cooling system is
operating. More information on duct leakage can be found in Chapter 9.
6

Chapter 2 System Components
Chapter 2 System Components
This Manual includes operating instructions for the following models of Minneapolis Blower Door:
•Model 3/110V System
•Model 3/230 System
•Model 4/230V System (CE labeled fan and
controller)
Both the Model 3 and Model 4 Minneapolis Blower Door
systems are comprised of three separate components:
1. Blower Door Fan
2. Accessory Case with Test Instrumentation (building
pressure and fan flow gauges), Fan Speed Controller and
Nylon Door Panel
3. The Adjustable Aluminum Door Frame
While the Blower Door fan motor, flow sensor and speed controller vary slightly between the three different
Minneapolis Blower Door systems, the other system components are identical.
PC based test analysis software (TECTITE™) is also available to help you document and analyze Blower Door
test results.
2.1 Blower Door Fan
The Blower Door fan consists of a molded fan housing with a 3/4 h.p. permanent split capacitor AC motor. Air
flow through the fan is determined by measuring the pressure at the flow sensor which is attached to the end of
the motor. When the fan is operating, air is pulled into the inlet side of the fan and exits through the exhaust side
(a metal fan guard is bolted to the exhaust side of the fan).
The Blower Door fan can accurately measure airflow over a wide range of flow rates using a series of calibrated
Flow Rings which are attached to the inlet of the fan. The standard Minneapolis Blower Door system comes
with 2 Flow Rings (A and B) capable of measuring flows as low as 300 Cubic Feet per Minute (cfm). Optional
Rings C, D and E are available which allows flow measurements as low as 85, 30 and 11 cfm respectively.
Model 3 Fan with Rings A and B
7

Chapter 2 System Components
The main distinguishing feature between the Model 3 and Model 4 fans is the shape of the flow sensor attached
to the fan motor. Model 3 fans (both 110V and 230V) use a round white plastic flow sensor, while the Model 4
fan uses a flow sensor manufactured out of stainless steel tubing.
Model 3 Fan and Flow Sensor Model 4 Fan and Flow Sensor
2.1.a Determining Fan Flow and Using the Flow Rings:
Fan pressure readings from the flow sensor are easily converted to fan flow readings by using a Flow
Conversion Table (see Appendix B), by reading flow directly from the Blower Door gauge(s), or through the
use of the TECTITE Blower Door Test Analysis Software. The Blower Door fan has 6 different flow capacity
ranges depending on the configuration of Flow Rings on the fan inlet. Table 1 below show the approximate flow
range of the Blower Door fan under each of the 6 inlet configuration. The greatest accuracy in fan flow readings
will always be achieved by installing the Flow Ring with the smallest opening area, while still providing the
necessary fan flow. Importantly, when taking Blower Door measurements, stand at least 12 inches from the side
of the fan inlet. Standing directly in front of the fan may affect the flow readings and result in erroneous
measurements. Table 1: Fan Flow Ranges
To install Flow Ring A, place Ring A onto the inlet side of the fan
housing and rotate the 8 fastener clips attached to the housing flange so
that they rotate over the edge of Ring A and secure it in place.
Fan Configuration
Flow Range (cfm) for
Model 3 Fan
Flow Range (cfm) for
Model 4 Fan
Open (no Flow Ring)
6,100 - 2,435
4,850 - 2,090
Ring A
2,800 -915
2,500 -790
Ring B
1,100 -300
900 -215
Ring C
330 -85
260 -45
Ring D
115 -30
125 -30
Ring E
45 -11
50 -11
8

Chapter 2 System Components
To Install Flow Ring B, place Ring B in the center of Ring A and
rotate the 6 fastener clips attached to Ring A so that they rotate over
the edge of Ring B and secure it in place.
In addition to Flow Rings A and B, the standard Minneapolis Blower
Door comes with a solid circular No-Flow Plate to seal off the fan
opening. The No-Flow Plate is attached to Ring B in the same manner
that Ring B attaches to Ring A.
The No-Flow Plate and Rings A and B can be removed separately, or
all 3 pieces can be removed at the same time by releasing the 8
fastener clips holding Ring A to the fan housing.
Installation and use of optional Flow Rings C, D and E are discussed
in Appendix C.
2.2 Test Instrumentation (Pressure and Fan Flow Gauges)
This manual covers three instrumentation options typically used with the Minneapolis Blower Door; the DG-
700 Digital Gauge, the DG-3 Digital Gauge, and the APT System.
2.2.a DG-700 and DG-3 Digital Pressure Gauges:
The DG-700 and DG-3 are differential pressure gauges which measure the pressure difference between either of
their Input pressure taps and its corresponding bottom Reference pressure tap. Both gauges have two separate
measurement channels which allows you to monitor the building pressure and fan pressure (air flow) signals
during the Blower Door test (the DG-700 allows for simultaneous display of both channels, while the DG-3 can
display one channel at a time). In addition, both gauges are able to directly display air flow through the Blower
Door fan (the DG-700 can display fan flow in units of cfm, l/s and m3/hr). The digital gauge is shipped in a
separate padded case which is stored in the Blower Door accessory case. Also included is a black mounting
board to which the digital gauge can be attached using the Velcro strips found on the back of the gauge.
The DG-700 can also be used to automate control of the Blower Door fan using the following two features:
•The-DG-700 can be used along with TECTITE software and a user supplied laptop computer to
conduct a fully automated Blower Door test. When conducting automated tests, the speed of the Blower
Door fan is computer controlled while the TECTITE program simultaneously monitors the building
pressure and fan flow using the DG-700’s two pressure channels. Test results are recorded, displayed on the
screen, and can be saved to a file. Note: Automated testing requires the TECTITE software and special
cabling.
•Newer DG-700 gauges have a built-in “Cruise Control” feature which allow the user to control the
Blower Door fan to maintain a constant building pressure, without using the TECTITE software or a laptop
computer.
9

Chapter 2 System Components
2.2.b Automated Performance Testing System™:
The Automated Performance Testing (APT) system performs fully automated Blower
Door tests from a user supplied laptop or desktop computer using TEC’s TECTITE
software. The TECTITE software allows the user to select among various airtightness
testing procedures, including a cruise control option which maintains the building at any
user-defined pressure. The APT system automatically adjusts the speed of the Blower
Door fan while simultaneously monitoring the building pressure and fan flow using 2
on-board differential pressure channels. Test results are recorded, displayed on the
screen, and can be saved to a file.
If the APT system contains more than 2 installed pressure channels, the additional
channels can be used to monitor and record pressures in attached zones (e.g. attic or
crawlspace) during the automated Blower Door test.
The APT system consists of the following components:
•One Data Acquisition Box (DAB) with 2 to 8 on-board pressure channels and
phone jacks for 8 voltage input channels.
•One 6’ serial cable (w/ 9 pin connectors) to connect the DAB with your
computer.
•One 12V power supply for the DAB.
•One CD containing the TECTITE software.
The Data Acquisition Box (DAB) comes fastened to a black plastic mounting board. The mounting board may
also contain two electrical outlets which can be used to power the Blower Door fan, DAB or a lap-top computer.
Note: When using an APT system, only automated Blower Door testing can be conducted because the APT’s
DAB does not have a built-in display. Manual testing must be done with a DG-700 or DG-3 gauge.
DG-3 Pressure Gauge
DG-700 Pressure Gauge
10