Significantly better energy cost balance due to optimized high-speed doors

Hohe Geschwindigkeiten und gute Dämmung von Industrietoren können zu signifikanten Energieeinsparungen führen. © Efaflex

Whether workshop or warehouse: industrial doors can open the way to heat and cold losses in any industrial building – but at the same time also offer considerable savings potential. If they are open or poorly insulated, there is inevitably a significant exchange of air, which significantly increases the heating or cooling needs of the building.

As early as 2013, the Technical University of Munich was able to prove in a study that hold-open times, opening and closing speeds, and insulation of industrial doors have a lasting effect on the energy balance of the entire building. High energy efficiency not only benefits the environment, but also the budget. For this reason, Efaflex Tor- und Sicherheitssysteme GmbH & Co. KG develops high-speed doors that feature particularly fast opening and closing speeds – up to 4 m/s – as well as optimal thermal insulation with U-values down to 0.6 W/(m2K). This corresponds to the best front doors available today. Users can use the new EFA Energy-Saver to calculate the actual savings of the respective doors in their individual operating environment. For example, the tool for the EFA-SST ISO 60 model shows exemplary CO2 and cost savings of around 70 percent compared to a conventional sectional door.

“CO2 emissions can be reduced by not consuming energy unnecessarily,” says Jan Hauffe, head of product management at Efaflex. “Here, the ecological factor is also an economic factor: if investments are made in the energy and CO2 efficiency of the buildings, this is already reflected positively in the cost balance in the medium term.”

The large number of areas of application in the fields of industry and production as well as commerce, trade and services opens up different starting points when it comes to sustainable building design. However, many industrial buildings generate high heat loads, depending on the purpose of the halls and rooms, for example due to running production facilities or heating/cooling equipment. As a result, the sectors mentioned above “consume” a total of more than 40 percent of final energy in Germany and cause around 30 percent of direct CO2 emissions.

Not insignificantly involved in this circumstance is an element that can be found in any industrial building: Industrial doors. Ideally, they noticeably reduce the exchange of air between indoor and outdoor areas. In this way, they can play a significant part in curbing costly cold and heat losses building-wide – although the extent depends on their respective properties in terms of thermal insulation, speed and hold-open time.

“Door systems contain significant potential for energy savings,” confirms Dr. Timm Rössel, Managing Director of Etanomics Service GmbH and co-author of the TU Munich study. “In today’s energy-efficient and sustainable construction, door systems should therefore be integrated into building and facility design at an early stage.”

Efaflex roller doors achieve the same insulation values as the best front doors with 0.6 to 0.8 W/(m2K). © Efaflex
Efaflex roller doors achieve the same insulation values as the best front doors with 0.6 to 0.8 W/(m2K).
© Efaflex

Closing speed and insulation as key factors

With the aim of improving the energy efficiency of buildings in the long term and sustainably, Efaflex develops door systems that minimize heat or cold losses through short hold-open times and very good insulation and sealing properties. “As early as 2013, the study by the Technical University of Munich showed that the heat demand caused by the door can be reduced by up to 30 percent by using fast-running doors and avoiding longer, continuous open times,” confirms Rössel.

However, in order for the advantages to be reflected later in the energy cost balance sheet, the industrial door must also be designed for the respective application environment. “The weighting of the individual features of a model depends on the specific application,” explains Hauffe. “Is the door located in a particularly temperature-sensitive area? Also, the operating periods and corresponding number of load changes must not be neglected.”

The EFA-SST high-speed spiral door combines speed with particularly good insulation, while the EFA-STR model with top speeds of up to 4 m/s prevents large amounts of heat or cold from escaping during the critical opening phase.

The particularly fast gates are best suited for indoor logistics operations. In sensitive transitions between two temperature zones, for example as an access door in cold stores for food storage, on the other hand, it is primarily a matter of careful thermal insulation: The EFA-SST ISO 60, which was specially designed for this purpose, has 60 mm thick EFA-Therm insulating lamellas, which minimize heat transmission to a much greater extent. Together with the horizontal hinged sealing profile, which ensures effective sealing to the top over the entire width of the door, the insulation ensures optimum insulation with a U-value of up to 0.8 W/(m2K).

Full transparency on savings potential

In order to prove the real cost savings of high-speed doors compared to conventional sectional doors, Efaflex has now developed the EFA Energy-Saver based on the study results of the Technical University of Munich. By entering some key data such as passage height and width, internal temperature, load changes per day, days of use per year, and heating costs per kilowatt hour, it is easy to calculate the annual savings of a high-speed door compared to a sectional door.

The results are broken down into kilowatt hours, CO2 emissions and financial savings. In addition, it is possible to see which characteristic of the industrial door – opening and closing speed, open time, and insulation or tightness – accounts for which share of the savings.
With the help of the EFA Energy Saver, a partial saving of 5,078 kWh and 1.34 t CO2 per year can be calculated for the EFA-SST ISO 60 compared to a conventional sectional door, which is specifically due to the high opening and closing speed. This corresponds to a cost advantage of 1,220 euros. In addition, there is the U-value of the EFA-SST ISO 60, which quantifies the heat transfer.

Due to the good insulation of this model, which avoids thermal bridges by design, a further saving of 507 kWh and 0.13 t CO2 is achieved. This reduces the cost by a further 114 euros, or 38.3 percent, compared with the reference gate. “With the help of the EFA Energy Saver, the real savings of high-speed doors can be calculated and shown in three categories. In this way, you can see at a glance how the respective door has a very concrete effect on the energy cost balance, taking into account the current heating cost tariffs,” Hauffe sums up.


Efaflex Tor- und Sicherheitssysteme GmbH & Co KG was founded in 1974 and has its headquarters in Bruckberg near Munich. The company specializes in the development and manufacture of industrial doors and is the world market leader in the field of high-speed doors. Designs range from spiral, rolling and folding doors to clean room, freezer and machine protection doors used in a wide variety of industries. The doors are sold on five continents and can also be purchased from subsidiaries in Germany, Austria, Switzerland, Great Britain, Slovenia, Czech Republic, Poland, Belgium, Russia and China. In addition, Efaflex offers a repair and maintenance service. The company employs around 1,400 people worldwide.