GRABEN, Germany — Ian Jack, of Blower-Door-XXL (Lemgo, Germany), was recently recognized by Guinness World Records for executing the world’s largest blower door test.

Jack achieved the record using 15 Retrotec 3300 test fans with 120,000 cfm, as well as a large 60,000-cfm fan on a 37-million-cubic-foot building in Graben, Germany.

His team used depressurization testing along with an infrared camera to locate leaks. Loading ramps, gates, elevator shafts, and emergency exits were all identified as air leakage contributors. Yet, despite the large amount of leakage, sealing to meet the standard may not have been the most challenging part.

“The test was tiring,” said Jack. “However, the morale was high and we had the feeling that we mastered the challenge.

“Convincing the client of the benefit of testing was also tough. Getting the building prepared for the test is always a challenge too,” he said. “All interior doors must be open, of course, not easy in a high security building. Where to get 15 16A power sockets was also not easy. Shutting down the ventilation and sealing some of the vents on the roof when it’s cold is also difficult.”

Despite the difficulties, Jack’s seasoned team of large building testers successfully met their standards, as well as gaining the world record for largest building tested with blower doors.

“Energy savings on a large scale can be made on such buildings. All you need are enough fans,” said Jack. “Testers think it can’t be done, or that they don’t have the required power. Maybe they overestimate the leakage area, as it was approximately 14 square meters on this building. Large buildings also lose lots of energy and have the same problem as domestic dwellings — just on a larger scale.”

For more information on the Guinness World Record blower door test, visit

Publication date: 04/23/2012