Hygienic design air/water heat exchangers

Climate control of enclosures using water cooling is highly efficient, especially if there is already a central cold water supply available in the production plant. The new hygienic design air/water heat exchangers from Rittal are suited to the food industry, where hygiene standards are exceptionally stringent.

Hygiene is an absolute must in the food industry: machinery, plant and components must readily withstand daily cleaning with pressure washers and jet steam cleaners. All surfaces must also be easy to clean, and/or designed to prevent contaminants from adhering to them.

Use water cooling to dissipate heat

Liquid cooling of enclosures offers a number of benefits: Because water has a higher thermal capacity than air, liquid cooling can dissipate large quantities of heat. What’s more, industrial environments often already have a central cooling water supply available that can be used for enclosure cooling. All that’s left to do is to mount suitable air/water heat exchangers on the enclosure. With Hygienic Design, it is particularly important that no air exchange takes place between the enclosure and the environment.

Rittal has revamped its air/water heat exchangers, and can now offer its clients in the food industry two variants of Hygienic Design. Air/water heat exchangers for wall mounting can supply cooling outputs of either 0.65 kW or 1.2 kW. The hygienic design reduces the risk of contamination in the food industry, thus helping to ensure product safety.

Modified design

Rittal has modified the design of Hygienic Design in a number of respects.

For example, the attachment to the enclosure wall using threaded bolts and nuts has been designed so that the screw fastening is not visible from the outside. The enclosure is made from stainless steel with a brushed grain size of 400, producing a surface roughness Ra of less than 0.8 μm. The smooth surface finish is easy to clean and disinfect. There are no hard-to-clean gaps where contamination could collect.

The silicone seal between the enclosure and the case prevents the transfer of colourants, flavourings and unwanted odours. The seal eliminates gaps between the air/water heat exchanger and the enclosure which would be difficult to clean.

The seals are available as spare parts, and are easily replaced in the event of mechanical damage. The seals are dyed blue in accordance with FDA Guideline 21 CFR 177.2600, making them clearly distinguishable from contaminants such as food residues. The flat seals on the water connection fittings are likewise dyed blue, and geometrically designed to sit flush against the shape of the fitting. A metal end stop prevents compression of the seal, so that edges cannot protrude and allow contaminants or micro-organisms to accumulate.

Tested hygiene

The top of the enclosure tilts forwards by 30 degrees. This prevents objects from being placed on top of the enclosure, while at the same time ensuring that liquids, such as detergents and disinfectants, run off quickly.

Air/water heat exchangers have protection categories of IP56/59, meeting the demanding requirements of pressure washing and steam cleaning.

The air/water heat exchangers have C-UR and CSA approval, making them suitable for international use.

The Hygienic Design was tested by the DGUV Food department testing and certification agency in accordance with GS-NV 6 (test principles for hygiene). The devices comply with standard DIN EN ISO 14159:2008 and are suitable for use in the food sector in conformity with DIN EN 1672-2:2009.