Today, many builders are routinely building houses that are very airtight, often without realizing it. The common use of building wraps, moisture barriers, high efficiency windows and even simple plywood sheathing all have direct effects on reducing air leakage and infiltration. An airtight house has many fewer openings through which fresh air can enter. Without the addition of mechanical ventilation, a tight house can result in stagnant air, less natural ventilation and dissatisfied homeowners. On the other hand, houses with large amounts uncontrolled air leakage are equally troublesome with comfort complaints due to drafts, building failures and high energy bills.

Despite the growing importance of house airtightness, few builders, architects or homeowners know how tight their houses are. Until recently, the building community has tended to rely on subjective estimates of airtightness. Unfortunately, it is impossible to accurately estimate the tightness level of a building by visual inspection alone. And without knowing the airtightness level, it is difficult or impossible to design for effective approaches to ventilation and air quality, or to accurately diagnose performance problems.

Instrumentation Options

• The DG-700 Digital Pressure and Flow Gauge is the latest instrumentation option for the Model 3 Blower Door. The DG-700 contains 2 precision pressure sensors which provide simultaneous display of both building pressure and Blower Door fan flow readings. It's specialized "Baseline" and "CFM @50" features makes it extremely easy to get quick and accurate airtightness test results. In addition, the DG-700 can be used along with a laptop computer and specialized TEC software to conduct fully automated Blower Door tests.
• The Automated Performance Testing (APT) System fully automates the Blower Door test from your laptop computer. Automatically adjusts the speed of the fan while simultaneously monitoring building pressure and fan flow using 2 on-board pressure channels. The APT System can be purchased with up to 6 additional pressure channels to simultaneously monitor multiple building zone pressures during a Blower Door test.

There are more than a million miles of duct work in U.S. homes. And industry experts estimate that more than two-thirds of them are leaky enough to justify sealing or repair. Leaky ducts can significantly increase air conditioning and heating bills, dramatically reduce equipment capacity and performance, as well as result in potentially dangerous indoor air quality problems. In fact, duct leakage is responsible for many of the comfort complaints experienced by homeowners today.

Today's building performance test procedures require diagnostic tools that are versatile, accurate and easy to use. The Energy Conservatory's DG-700 Pressure and Flow Gauge was designed to meet these needs.

DG-700 Pressure and Flow Gauge The DG-700 Pressure and Flow Gauge is a multi-functional differential pressure gauge with 2 independent pressure sensors. In addition to providing high-resolution pressure measurements, the DG-700 is programmed to operate with other Energy Conservatory test devices to provide air flow measurements during building performance test procedures. The DG-700's simultaneous display of two pressure channels and air flow measurement features make it ideally suited for a wide range of building performance applications including airtightness testing of buildings and duct systems, air handler flow measurements, building depressurization and combustion safety testing.

DG-700 Features:

• Simultaneous display of 2 independent differential pressure channels.
• Bi-directional, precision pressure measurement up to 1,250 Pa (5" w.c.). The DG-700 can display pressure readings in both Pascals and " w.c.
• Auto-zeroing of both channels eliminates sensitivity to orientation and temperature, making it perfect for hand-held operation.
• Four separate time-averaging modes (1, 5, 10 second & long-term) allow you to accurately measure fluctuating pressures.
• Programmed to display air flow readings for Minneapolis Blower Door and Duct Blaster systems, TrueFlow Air Handler Flow Meter and Exhaust Fan Flow Meter (air flow units can be displayed in cubic feet per minute, cubic meters per hour and litres per second).
• "Baseline" feature allows the user to measure and record a baseline pressure reading, and then display the baseline adjusted reading.
• Specialized @50 and @25 test modes make it simple to conduct one-point airtightness tests of buildings and duct systems.
• The DG-700 can be used along with a computer and specialized TEC software to conduct automated Blower Door tests, and for data logging of pressure measurements from both channels.
• Programmed to display velocity measurements using a Pitot tube (velocity units can be displayed in both feet per minute and meters per second).

• Computerized Blower Door fan control and data collection improves the accuracy and repeatability of test results by reducing wind and operator errors.
• Automated operation eliminates time spent zeroing gauges and adjusting fan speed.
• Pre-programmed test protocols ensure that the tests are done the same way every time. The system even tells you when to switch flow rings.
• Eliminates the need to measure and record offset pressures due to wind and stack effect - the APT system automatically does this at the beginning and end of each test.
• Cruise Control allows you to maintain a constant building pressure during diagnostic and sealing procedures.
• Built-in data analysis, report generator and file storage features.
• Requires airtightness testing software (TECTITE) and cabling.

Data Logging Features

• The APT system is the only data logger with built-in high resolution pressure channels that continuously monitor changes in building pressures caused by wind, stack effect, or mechanical systems such as fans and duct system imbalances.
• Available with two to eight precision pressure channels.
• Includes 8 analog voltage channels that can be connected to optional sensors for monitoring carbon monoxide, relative humidity, temperature and other important performance indicators.
• The data logging software (TECLOG) includes a graphical display that allows you to observe data as they are being collected and saved.
• Data files can be easily converted to ASCII format for input into other analysis programs.
• Optional sensors available from TEC include carbon monoxide, relative humidity and temperature.

The TrueFlow Air Handler Flow Meter is designed to provide a simple and accurate measurement of airflow through residential air handlers. The TrueFlow Meter temporarily replaces the filter in the air handler distribution system during the airflow measurement process. If the filter location is directly adjacent to the air handler, the TrueFlow Meter will measure the total air handler flow. If the filter is located remotely at a central return, the TrueFlow Meter will measure airflow through the central return.

• Easy and fast to use in the field. The TrueFlow Meter provides direct CFM readings in 2 to 3 minutes without extensive calculations or setup.
• Designed to measure flow through air handlers rated from 1 to 5 tons.
• Can be used in a wide range of return plenums and air handler fan configurations.
• Adjustable sizing to fit standard and custom filter slots.
• Proven to be more accurate than the single-point temperature rise method and easier than the fan curve method.
• Use with any manometer which has a resolution of 1 Pascal or 0.004" w.c..

• TrueFlow Kit includes two calibrated metering plates, 8 spacers, static pressure probe, tubing, carrying case, flow conversion table and operation manual.
• Fits most standard size filter slots including:

• Flow accuracy is +/- 7% for most applications when used with a 1% accurate pressure gauge.
• Instrumentation options include TEC's DG-700 gauge, a set of Magnehelic gauges (60 Pa and 250 Pa), or use your own manometer.

Specifications subject to change without notice.

The Energy Conservatory
2801 21st Avenue South
Minneapolis, MN 55407
612-827-1117
Visit The Energy Conservatory Web site