The company

BlowerDoor GmbH has its premises in the Energie- und Umweltzentrum am Deister (or e.u.[z.], a non-profit association focusing on renewable energy), about 25 km southwest of Hanover, Germany. As a training center, the e.u.[z.] provides information, consulting, and training in the fields of energy- and resource-efficient construction, building physics, and renewable energy. The 18,000 m² site is home to a number of different companies that successfully implement state-of-the-art energy concepts.

Since 1989, the Ingenieurgemeinschaft Bau+Energie+Umwelt (an engineering company specializing in building physics and optimizing energy efficiency) had been pioneers in the fields of air tightness, BlowerDoor measurements, and BlowerDoor product development in Germany. Having sold the first BlowerDoor devices and successfully hosting the first BlowerDoor Symposium – which has meanwhile become an annual event – they founded the BlowerDoor GmbH in 1999. Our know-how is reflected in both the hardware and software of our BlowerDoor measuring technology. After all, in addition to comprehensive consulting, product development and qualification are our core activities. The committed and motivated members of our BlowerDoor team at our headquarters in Springe-Eldagsen are pleased to provide customer care to clients in Germany as well as more than 30 other European countries. We are proud to say:

We are the experts in air-tightness measuring systems!

BlowerDoor GmbH is domiciled in the Centre for Energy and Environment

Germany's market leader: the Minneapolis BlowerDoor

>The Energy Conservatory<
(Manufacturer)

20 Years of BlowerDoor

How it all started...

Uwe Weltecke (founder of Isofloc Wärmedämmtechnik GmbH, a company specializing in thermal insulation technology), while in the US, discovers the Minneapolis BlowerDoor. His business associate and cofounder of the Ingenieurgemeinschaft Bau + Energie + Umwelt GmbH Robert Borsch-Laaks [an engineering company specializing in construction, energy, and the environment] is absolutely enthusiastic about the significance of air-tightness measurements and imports the first Minneapolis BlowerDoor (Model 2) to Germany.

Milestones

Today, the Minneapolis BlowerDoor is the leading air tightness measurement device in Germany and one of the most successful worldwide. In addition to Germany, the BlowerDoor GmbH serves more than 30 European countries.

2009

TECLOG Multifan was developed to measure large buildings with multiple BlowerDoor fans. The module consists of 3 BlowerDoor fans and 2 digital DG-700 pressure gauges. It is possible to measure buildings with an envelope area of approximately 7,000 to 36,000 m² or an internal volume of up to 450,000 m³. For larger buildings several Multifan systems could be combined.

2008

Hardware and software are further optimized, as is the handling of the Minneapolis BlowerDoor. Model 4.1 is launched. It includes, among other features, an extended measuring range from 19 to 7,200 m³/h and a speed-control function for one-point measurements without the need for a laptop for quality assurance and first analysis, as well as the TECTITE Express software with multiple diagram and pause function.
Paul Simons takes over the management.

2007

Februar 2007 Garching: Office building with 90,000 m³ interior volume:
8 BlowerDoor fans are installed in panels with 2 and 3 apertures. During the measurement, the fans are turned off one after the other and covered (with lids or caps).

2006

The first European BlowerDoor Symposium takes place in Fulda.
The development of the "a-value testing kit" software for determining the permeability of window joints is completed successfully.

2004

FLIR thermography cameras are added to the product range of the BlowerDoor GmbH. Electronic proprietary calibration via Mensor is started.

2003

The development of the laptop-controlled digital pressure gauge DG-700 (2 channels) for the BlowerDoor measurement is completed successfully. The DG-700 replaces the analog pressure gauge and becomes the new measuring standard. The measuring accuracy of the DG-700 is at ± 1% and allows for very accurate measuring results. The proprietary software “Extinction Gas Holding Times” complements the product line.

2002

With the introduction of the EnEV, the German Energy Savings Regulation, demand from other European countries also increases rapidly, with sales to Denmark, Norway, Sweden, and Italy, among others.
The “BlowerDoor plus” software is developed, which allows for the evaluation of BlowerDoor measurements with several BlowerDoor fans. The first measurements of clean rooms (laboratories, production facilities, and operating theaters) are carried out successfully using the Minneapolis BlowerDoor.
The fan inspections recommended by the Fachverband für Luftdichtheit, the association for air-tightness in buildings, further expand the service offer provided by BlowerDoor GmbH.

2002: BlowerDoor measurements of large buildings with 2 of 4 fans installed - at the zero-emission plant of company Solvis/Braunschweig, Germany.

2000

The Fachverband für Luftdichtheit im Bauwesen e. V., the German association for air tightness in buildings, is founded. BlowerDoor GmbH becomes a member.

FLiB e. V., the German association for air tightness in buildings, is founded at the e-u-z
Center front: Dr. Monika Hall, Sigrid Dorschky, Dr. Achim Geißler

2000: Construction of the Philbus (Passive House for Innovations, Air Tightness, Building and Solar Technology) on the premises of the e-u-z. BlowerDoor measurement as an early test for quality-assurance purposes.

1999

In founding the BlowerDoor GmbH, engineering and commercial activities are separated and intensified. The BlowerDoor GmbH, in addition to selling the BlowerDoor measuring technology, also offers manufacturer’s calibration for the analog pressure gauge as well as for the digital pressure gauges DG-3E and APT (the so-called Mikrotektor is used as a reference).
The company management is represented in standardization committees.

October 1999: 4^th BlowerDoor Symposium with 180 participants

October 1999: Trade exhibition during the 4th BlowerDoor Symposium. From left to right: Frank Spevak, Gary Nelson und Robert Nevitt (The Energy Conservatory/Minneapolis), Sigrid Dorschky, Hermann Wiefels, Stefanie Rolfsmeier, Wilfried Walther, Lothar Gerbermann, Paul Simons

1999: Taking the ICE-train to the BlowerDoor test. Sigrid Dorschky with BlowerDoor fan, disassembled wooden frame and transport bag with measuring equipment.

1999: Frank Möbius (co-founder of the e-u-z) talks to Hans Mönninghoff (Environmental Officer of the City of Hanover and co-founder of the e-u-z) and Gary Nelson (The Energy Conservatory/Minneapolis)

1999: Sigrid Dorschky teaches a seminar

Hands-on workshop at the NEGH (low energy building)

1998

The Minneapolis BlowerDoor Model 4 with the ATP differential pressure gauge (4 to 8 channels) is introduced, including the TECTITE Express software for the implementation of automated BlowerDoor measurements with one or more BlowerDoor fans. The first measurements of large buildings (> 4,000 m³ of internal volume) are conducted using two or more BlowerDoor fans. The Minneapolis BlowerDoor is awarded the CE label (product-safety label in accordance with EU-legislation), and the TÜV Munich (technical testing and inspection organization) confirms its measuring accuracy. An announcement in the German Federal Gazette declares the air tightness of the building envelope to be state-of-the-art.

September 1997: Demonstration of a BlowerDoor measurement - top floor of the main building of the Energie- und Umweltzentrum - on the occasion of the 3^rd BlowerDoor Symposium. Pressurisation makes the fog escape through leaks.

September 1997: 3^rd BlowerDoor Symposium with 120 participants. From left to right: Gary Nelson (The Energy Conservatory/Minneapolis) and Robert-Borsch-Laaks in the marquee.

1997: Trade exhibition during the 3^rd BlowerDoor Symposium. From left to right: Sigrid Dorschky, Gary Nelson, Ireene Geese and visitors.

1995

The stipulations of the German Thermal Insulation Regulation give new importance to the issue of air-tightness. The wooden frame is replaced by an aluminum frame developed especially for the Minneapolis BlowerDoor.

1994

The first digital differential pressure gauge DG-3E (1 channel) is launched.

1993

The 1^st BlowerDoor Symposium takes place, featuring presentations on applications of the BlowerDoor in thermography-aided leakage detection. By now, seven national and three international BlowerDoor Symposia have been held at different venues across Germany. The first air-tightness test of a Passive House is conducted in Darmstadt.

18 November 1993: BlowerDoor Symposium at the e-u-z. 32 experts from 13 testing teams participated. From left to right: Sue Sheehan (interpreter), Gary Nelson (The Energy Conservatory/Minneapolis), Robert Borsch-Laaks (co-founder of the e-u-z), Paul Simons and Sigrid Dorschky (both Ingenieurgemeinschaft Bau + Energie + Umwelt GmbH).

1992

Sales and distribution are expanded to other German-speaking countries.
In Switzerland, a comparative measurement with a Minneapolis BlowerDoor and a self-built Swiss model are implemented. Not least due to its easy handling, the Minneapolis BlowerDoor comes out as the clear favorite. Model 3 is introduced and the aperture plate is replaced by the rings A-C.

23 January 1992: Klaus Michael (Niedrig-Energie-Institut Detmold/Low-Energy Institute Detmold) adopting a typical posture: "securing a large provisional sealing (door opening at 50 Pa negative pressure)"

18 December 1992: Comparative measurement with a Minneapolis BlowerDoor and a self-built Swiss air tightness measuring device (consisting of a 2 m pipe conduit and a wooden board) in Switzerland. Due to its easy handling, the results favour the Minneapolis BlowerDoor.

1992: BlowerDoor Model 3 is introduced (white fan), aluminium frame with a horizontal cross bar and analogue pressure gauges screwed to the door panel. Later, pressure gauges and a controller were fixed to the frame and an additional cross bar was added.
Compare: The previous Model 2 came equipped with a reduction plate and wooden frame.

1991

The first Minneapolis BlowerDoor is sold in Germany. Air tightness measurements of the first zero-energy house are conducted in Dörpe (Germany).

1991: Minneapolis BlowerDoor model 2 with wooden frame and analogue pressure gauges. Wilfried Walther controls fan speed. Peter Merl enters the test results in the microcomputer.

1991: e-u-z-Baufachtagung, a specialist conference on construction, in a relaxed atmosphere: the participants ame from alternative engineering and contracting companies that focused on energy efficiency.

8 February 1991: First BlowerDoor measurement of a zero-energy house in Dörpe, Germany. Result: air-change rate = 0.9 1/h. For comparison: the mean value of the measurements from the Hessian low-energy-house funding program from 1990 to 1993 was at 3.7 1/h.

Indoor shot: thermography for leakage detection during a BlowerDoor measurement

1989

The Ingenieurgemeinschaft Bau + Energie + Umwelt GmbH, housed on the premises of the Energie- und Umweltzentrum am Deister [a non-profit association focusing on renewable energies], buys the first Minneapolis Blower Door (Model 2 with analog pressure gauges and wooden frame). First air-tightness measurements are conducted in Hesse and Schleswig-Holstein.