Connection details in cold store and deep freeze store construction

Avoidance of thermal bridges and water vapour diffusion

The avoidance of thermal bridges and water vapour diffusion is a central theme in the construction of cold stores and deep freeze stores. Firstly, it is necessary to avoid unnecessary energy loss, for economic reasons, as refrigerating energy is 10 to 50 times more expensive than heat energy, depending on the system. Secondly - and no less important - the quality of the refrigerated goods can also be considerably impaired by thermal bridges and water vapour diffusion.

Water vapour-proof connecting structures

Sandwich construction is characterised by excellent heat insulation capabilities and by particularly impervious joint formation, with optional application of sealing on site. Therefore, when planning all related details, care must be taken that this advantage is not restricted by thermal bridges or by leaky connections. So, for example, with projecting sandwich panels, a so-called thermal cut-off should be used, which prevents heat conduction to the colder inner side. The load bearing capacity must naturally still be guaranteed if this detail is used. Wherever warm air can penetrate structural joints, suitable sealing measures which are proof against water vapour diffusion must be implemented.

Both the sandwich panels used for cold store and deep freeze store construction and their joining technique are free of thermal bridges and practically proof against water vapour diffusion. This is attributable to vapour-proof metal facings and the intelligent joint geometry of the joining technique. Despite this optimal starting situation, however, experience has shown that insulation and diffusion technology problems can result if connection details are not correctly resolved or executed from a building physics point of view. Special attention should be paid to the following points:

• Base formation
• Attic formation
• Ceiling-wall connection
• Transverse joint formation for wall
• Corner formation
  

  top

Abb. 4.3.1 Connecting structures that are free of thermal bridges and are water vapour-proof can be produced with modern sandwich panels. The picture shows the Langnese-Iglo central deep freeze warehouse in Reken, Germany. Architects: Plettenberg, Seeheim-Jugenheim, Germany

Base point formation

Fig. 4.3.2 shows an example of how the wall/floor transition can correctly meet the building physics requirements by using vertically installed sandwich panels and conventional floor insulation.

Thermal cut-off

The steel facing on the sandwich panels is separated in the area of the floor insulation, thereby largely excluding heat conduction. It must be ensured that the panel joins are optimally sealed, particularly on the outside of the building.

Vapour barrier and moisture barrier

An adequate moisture barrier - such as bitumen sheeting, for example - must be provided on the outer side of the floor insulation, which is equipped with a moisture barrier on the inner side of the cold store. These structural measures will prevent the risk of moisture damage to the insulation.

Under-freeze protection in deep freeze stores

Deep freeze stores are additionally equipped with heat conductors (e.g. under-freeze protection heat mats) beneath the floor insulation.

  top

Fig. 4.3.2 Example of a base formation for cold store and deep freeze store construction

  top

Figures 4.3.3 and 4.3.4 show a wall panel for cold store and deep freeze store construction with visible fastening, as well as the connection of these sandwich panels in the longitudinal joint.

Attic formation

Fig. 4.3.5 shows a detail of the attic formation for cold store and deep freeze store construction. The connecting structure shows the joining of wall panels in sandwich construction with a roof structure made of trapezoidal profiles, with heat insulation on the upper side.

Fig. 4.3.3 Joining of wall panels in the longitudinal joint

Fig. 4.3.4 Joining of wall panels in the longitudinal joint

  top

Fig. 4.3.5 Attic formation for cold store and deep freeze store construction

Ceiling-wall connection, transverse joint and corner formations

Figures 4.3.6 to 4.3.8 show examples of a ceiling-wall connection, a transverse joint formation of walls in cold stores and deep freeze stores, as well as a corner formation of sandwich panels for cold stores and deep freeze stores.

Fig. 4.3.6 Example of ceiling-wall connection of sandwich panels

  top

Fig. 4.3.7 Example of a transverse joint formation for horizontally installed wall sandwich panels

Fig. 4.3.8 Example of a corner formation with sandwich panels

Author:

Erwin Pesch
Dipl.-Ing. (FH)
Romakowski GmbH & Co KG, Buttenwiesen

  top