Not all enclosures are created equal for outdoor applications

The need for outdoor systems is increasing, due to the ever-expanding requirement for all things to be connected. This need will only increase but it is paramount that when a system is to be placed outside serious consideration, is given to the design of the housing that the critical infrastructure equipment, will sit in. Whether it be telecommunication, rail, airports or highways the overriding factors are the same.

Outdoor enclosures usually contain critical infrastructure equipment and as such we need to ensure that we are protecting that equipment. The key question from within industry is, why would you put equipment in an enclosure that isn’t specifically designed to work in that environment – an enclosure that will most likely leak, allow the equipment inside to overheat, or cause condensation during the winter months, as well as offering no form of security protection, against individuals who wish to gain access, to damage or remove the equipment.

In larger or more critical applications, the equipment placed internally will cost in excess of tens of thousands of pounds. Yet, in industry today more than ever before we are seeing businesses, choosing enclosures based on cost, rather than its ability to protect critical equipment. The enclosure itself, is just as important as the equipment it is protecting. It is key to bear in mind that if the enclosure fails, then so will the infrastructure it protecting.

When deciding on the most suitable outdoor solution for your project or network, Rittal’s experts advise you to decide what factors are most critical to you and your application and do your research before you select an enclosure, simply because its labelled ‘outdoor’ does not mean it has the right characteristics, to face the elements and securely protect your critical equipment. 

When an enclosure spends its lifetime outdoors, it will most likely face many years the hottest summers and the harshest winters, the most vulnerable part of the enclosure, is usually the door seals. Protecting the door seals means prevention from water leakage into the enclosure, this in turn increases the enclosures lifespan.

Water that is contaminated 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 with the requirement for a new door or a new enclosure. Adding an aftermarket seal often means a compromise and the IP rating no longer be valid. Water sitting on the seal during the colder months can freeze, as the water expands it will push the door away from the body of the housing and again, allows water inside. The best way to avoid these types of issues, is to choose an enclosure that has an overhanging roof, or a design that protects the doors seals. Standard enclosures that have no such design features, meaning often they are unsuitable to be placed outdoors.

Security and vandalism is one of the most concerning issues, when placing equipment outside and in public spaces. Selecting an enclosure, where careful consideration has been given to the design, to prevent vandalism or a member of the public gaining access to the enclosure and its contents is key.

Eradicating this possibility completely is difficult, but you can select an enclosure that has features that act as a deterrent. If someone wants to gain access then they will attack the weak points, of the enclosures first, these being the handle and lock then they may also look at the hinges of the door, if these are visible. Choosing an enclosure where different handle and lock options are available, having a lock inserted that requires a specific key and cannot be opened with a tool.

Hidden hinges on the doors also prevent unauthorised access, when trying to prevent someone gaining access. In most cases, this only needs long enough before they are disturbed, or they get bored of trying. Hidden hinges mean they cannot easily remove the doors, trying to gain access in other ways, will then mean bigger tools or more noise. Both of which again are usually a deterrent enough.

Double walled enclosures offer huge benefits for outdoor applications. Not only by helping to regulate UV solar gain, but a double walled enclosure means it is twice as hard to gain access to the equipment inside, if you don’t have the authority.

Double walled enclosures offer a chimney style effect, to eradicate some of the heat created by UV Solar gain. Whilst it does not stop all of the heat transfer, the outer layer assists with reflecting some of the light and what is transferred through the outer wall, some of this is then taken away between the two layers up and out of the roof area which is ventilated. Any heat gain left along with heat generated by the equipment inside, should then be able to be dealt with using a range of climate control options. This could be simple fans and filters, louvre arrangements or by using forced air cooling. Considering if the enclosure you have selected can offer these options as a retrofit at a later stage is key during the decision making process.

More often than not climate control is hugely overlooked in outdoor applications, the assumptions is that any heat loss generated by the internal equipment, will be lost through the transfer of the walls especially when placing an enclosures in a cooler country such as the UK.

Sadly experience tells us that this isn’t the case, sitting equipment in an enclosure works much like a flask, some heat transfer 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 huge amounts of 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 a shut down of the infrastructure network it is part of, then the outer walls can simply be replaced.

Lastly are you using the right materials? Stainless steel outside may sound suitable, however it’s costly and again not always the right option. Painted aluminium means lightweight but durable and has the ability to be handled more efficiently, dependent upon the application GRP may offer more benefits and would be significantly cheaper than stainless steel.

The next time you need an outdoor enclosure, really consider the enclosure as a critical piece of equipment, within the project or build. Selecting the right solution initially will ultimately save and you time and money overall.