Frequently Asked Questions
FAQ Index
- How long does it take to perform a standard airtightness test of a house or duct system?
- What are the advantages of conducting automated Blower Door tests using a DG-700 or Automated Performance Testing (APT) system?
- Which conferences should I attend to get the latest information on building diagnostic and repair techniques, and strategies to market and sell performance testing services?
- How often do I need to have my equipment recalibrated?
- Can I use a Duct Blaster fan to conduct airtightness tests of houses?
- What is a Pascal?
- I bought a Model 2 Blower Door fan many years ago and it still runs great, but the fan housing is getting pretty beat up. Is there anything I can do to revive it, short of replacing the whole fan?
- How does the new ASHRAE Standard 62.2 affect the recommended ventilation guideline in the TECTITE software?
- What effect do wind speed, variations in inside-outside temperature, barometric pressure and humidity have on Blower Door testing?
Q: How long does it take to perform a standard airtightness test of a house or duct system?
A: A standard airtightness test of a house can usually be completed in 30 minutes or less. Once you arrive at a house, the Blower Door can typically be installed in about 5 - 10 minutes. Additional preparation and inspection of the house prior to beginning a test adds another 10 minutes. At this point, a test of the house to determine the overall leakage of the envelope can be conducted in less than 5 minutes.
Once the simple airtightness test has been completed, additional diagnostic procedures to find and prioritize the major leakage sites can add another 20 to 45 minutes depending on the size and complexity of the house, and the procedures used.
A standard airtightness test of a duct system using a Duct Blaster usually takes a little longer than a house test (about 15 - 20 minutes more), due to the need to temporarily seal all registers and grills before starting the testing procedure. Use of an adhesive backed register sealing material, such as TEC's Duct Mask, can keep this additional time investment to a minimum.
Q: What are the advantages of conducting automated Blower Door tests using a DG-700 or Automated Performance Testing (APT) system?
A: With automated Blower Door testing, you will be able to perform more accurate and repeatable airtightness tests in windy weather conditions where manual testing is extremely difficult or sometimes impossible. By automating the test procedure, the DG-700 or APT system (along with the TECTITE software) is able to quickly gather and analyze hundreds of times more readings during a single test sequence than would be practical with a manual Blower Door test. Quickly collecting large samples of data in windy conditions greatly improves the repeatability of your test results.
Automated operation also eliminates many common operator errors and ensures that tests are performed the same way every time. During the automated test, the TECTITE software provides a series of on-screen messages to the operator to ensure that proper testing procedures are followed. It even tells you when to switch flow rings on the Blower Door fan. The software also detects common set-up and equipment problems (e.g. tubing connected to the wrong pressure tap) and provides appropriate warning messages to the operator.
If you are a frequent Blower Door user, automated testing should save you significant time. Automated operation eliminates the need to zero pressure gauges, adjust and tweak the fan speed, write down test data, and manually enter data into an analysis program. And the cruise control feature makes it much easier for 1 person to perform other test procedures such as pressure pan testing or zone pressure diagnostics.
Q: Which conferences should I attend to get the latest information on building diagnostic and repair techniques, and strategies to market and sell performance testing services?
A: Listed below are a number of national conferences which offer an excellent opportunity to keep abreast of the latest technologies, programs and strategies.
Affordable Comfort Conference
contact: Affordable Comfort, Inc. 800-344-4866 ph or
724-627-5200
724-627-5226 fax
www.AffordableComfort.org
ACEEE Summer Study on Energy Efficiency in
Buildings
contact: American Council for an Energy Efficient
Economy
202-429-0063 ph 202-429-0193 fax
www.aceee.org
Comfortech National Residential HVAC Seminar and
Comfort Technology Showcase
contact: Contracting Business 800-467-0997 ph
hvaccomfortech.com
Construction Business & Technology Conference
& Expo
contact: Journal of Light Construction 800-375-5981
ph
www.jlconline.com
Energy Efficient Builders Association (EEBA)
Conference and Expo
contact: Energy & Environmental Building Association, Inc.
612-851-9940 ph
612-851-9507 fax
www.eeba.org
GoodCents Conference and Exposition
contact: Good Cents 800-653-3445 ph
www.goodcents.com
Performance of the Exterior Envelopes of Whole
Buildings
contact: Oak Ridge National Laboratory 865-576-7942
ph
www.ornl.gov/buildings
Q: How often do I need to have my equipment recalibrated?
A: (click here for the Calibration and Repair of Test Instruments page).
Q: Can I use a Duct Blaster fan to conduct airtightness tests of houses?
A: Yes. The Duct Blaster fan's 1,350 cfm (cubic feet per minute) air flow capacity at 50 Pascals will allow you to conduct a complete airtightness test on most houses built to energy efficient airtightness standards. For example, the Duct Blaster fan can generate a 50 Pascal test pressure in a 3,000 square foot house built to a performance standard of 3.0 air changes per hour. For tighter houses (1.5 air changes per hour) the Duct Blaster fan can test a house up to about 6,000 square feet. We even make a nylon door panel for use with our adjustable aluminum frame that is sized just right for the Duct Blaster fan.
A: A Pascal is small metric unit of pressure. One Pascal is approximately 0.004 inches of water column. Commonly used airtightness test pressures of 25 and 50 Pascals are approximately 0.10 and 0.20 inches of water column respectively. 1 psi is approximately 7,000 Pascals. 1 lb/ft2 is approximately 50 Pa.
Q: I bought a Model 2 Blower Door fan many years ago and it still runs great, but the fan housing is getting pretty beat up. Is there anything I can do to revive it, short of replacing the whole fan?
A: Many of our customers are having their old Model 2 fan housing replaced with our Model 3 injection molded urethane housing. The old fan is first disassembled and inspected to see which parts may be reused. We try to use as much of the old fan as possible, and can typically re-use the motor, motor mount and fan prop.
The upgrade includes new electrical components, flow sensor and low-flow rings. The final product looks and acts just like a new Model 3 fan. The cost for a fan housing retrofit is usually about 30% less than purchasing a complete new Model 3 Blower Door fan. If your speed controller is currently mounted on the top of the fan housing, you will also need to purchase a new speed controller as part of the retrofit.
Q: How does the new ASHRAE Standard 62.2 affect the recommended ventilation guideline in the TECTITE software?
A: Click here for PDF file on ASHRAE 62.2 and TECTITE.
Q: What effect does wind speed, variations in inside-outside temperature, barometric pressure and humidity have on Blower Door testing?
A: Click here for PDF file on environmental effects and Blower Door testing.
