Minneapolis BlowerDoor: The Lord of the Rings!

Minneapolis BlowerDoor measurement systems are world leaders and have been used successfully for more than 35 years to determine the airtightness of residential and commercial buildings.  The unmatched accuracy and precision of BlowerDoor measurement technology is based on the design of the measuring rings and flow sensor, which has been proven over many decades. The components, which remain virtually unchanged to this day, are significant components of the BlowerDoor measuring fan. Volume flow measurement is based on what is known as pressure difference flow measurement, a widely used method that utilizes the Bernoulli principle.

The single-sided rounded measuring rings are optimized to create a stable flow profile during air flow. This method offers the great advantage of being largely independent of external disturbances such as wind and air turbulence. Each measuring ring has a defined measuring range that ensures a stable flow profile even at the lowest volume flows, thus offering high measuring accuracy. The shape and position of the flow sensor are designed to provide precise values for differential pressure measurement, similar to the measuring principle of a Pitot tube. The accurate measurement of the fan pressure difference at the measuring ring forms the basis for reliable determination of the volume flow.

It is easy to achieve repeatable measurement results in the laboratory under test conditions. However, the reality is different: the size and location of buildings, as well as wind and thermal conditions, have a major influence on airtightness measurements. Professional measurement teams need high-quality, reliable measurement technology to achieve accurate, correct and reproducible measurement results. Minneapolis BlowerDoor measurement systems have been meeting these requirements for decades. They are rightly the market leader in Germany and are among the most successful airtightness measurement systems worldwide.