Rittal’s product manager for industrial and IT enclosures, Emma Ryde, guides buyers through the process of choosing outdoor enclosures.
When an enclosure spends its lifetime outdoors, it will likely face years of hot summers and harsh winters. The most vulnerable enclosure element is usually the door seals. Protecting the door seals means preventing water entering the enclosure, thus increasing enclosure lifespan.
Contaminated water can cause degradation and over time the seal will fail. In many cases the seals can’t be replaced. This then becomes a costly fix, requiring a new door or enclosure. Aftermarket seals are often a compromise and may invalidate the IP rating. Water sitting on the seal during colder months can freeze. As the water expands it pushes the door away from the housing, allowing water inside. To avoid such issues, choose an enclosure with an overhanging roof or a design that protects the door seals. Standard enclosures without such design features are often unsuitable for outdoor use.
Security and vandalism are concerns when placing equipment outside and in public spaces. Select an enclosure with deterrent features. If someone wants to gain access then they will attack the weak points: handle, lock and door hinges. Choose an enclosure offering different handle and lock options, such as a lock which requires a specific key and cannot be opened with a tool. Hidden door hinges also prevent unauthorised access. Hidden hinges mean attackers cannot easily remove the doors and trying to gain access in other ways will mean bigger tools or more noise: both of which again are deterrents.
Double walled enclosures offer huge benefits for outdoor applications. They help regulate UV solar gain and a double walled enclosure is twice as hard to gain access to.
Double walled enclosures offer a chimney style effect, removing some of the heat created by UV solar gain. The outer layer reflects some of the light and some of the heat which is transferred through the outer wall is taken away between the two layers, up and out of the ventilated roof area. Any heat gain left, plus heat generated by the equipment inside, can then be dealt with using a range of climate control options. This maybe simple fans and filters, louvre arrangements or forced air cooling. Considering if the selected enclosure offers these options, as a retrofit at a later stage, is key during the decision making process.
Climate control is often overlooked in outdoor applications. The assumption is that heat generated by internal equipment, will be lost through the walls, especially when placing enclosures in cooler countries such as the UK. Sadly, experience shows this isn’t the case. Sitting equipment in an enclosure works much like a flask, some heat will be lost but how much heat is being generated in the first place? Has a thermal calculation been carried out? If the enclosure is subjected to higher ambient temperatures, or more equipment is installed at a later date, can cooling be added as an option later on? These are important points that, if considered early, can save time and cost further down the line.
Double walled enclosures also offer the benefit of refurbishment. In the event of damage, rather than removing the whole enclosure which would mean shutting down the infrastructure network it is part of, the outer walls can simply be replaced.
Lastly, what materials are being used? Stainless steel may sound suitable for outside applications but it is costly and not always the right option. Painted aluminium is lightweight, durable and can be handled more efficiently. Dependent on the application, GRP may offer more benefits and would be significantly cheaper than stainless steel.
The next time you need an outdoor enclosure, consider the enclosure as a critical piece of equipment, within the project or build. Selecting the right solution initially will ultimately save time and money.