Hello,
That’s a great question! All too often people get hung up on the IP rating of an enclosure that will be installed externally and forget about UV protection. Ironically, in the majority of cases it’s UV damage that will potentially cause problem rather than water ingress – most outdoor application only require IP54 protection unless they will be subjected to direct pressure washing or submersion in water.
Both polystyrene and polycarbonate enclosures offer benefits over traditional metal enclosures when housed outside as they aren’t susceptible to rust or corrosion. You’ve mentioned that strength isn’t an issue, so you’re right that the question ultimately must come down to UV protection.
The short answer is that Polycarbonate offers superior UV protection, so in a perfect world you’d always be better off with that. Of course, in reality cost does have to be considered – which is a tick in the box of polystyrene.
It’s hard to give precise figures on deterioration, but as a general rule I would expect a polycarbonate enclosure to last 5 – 10 times longer in an external environment before showing signs of UV exposure. In applications where the enclosures will be exposed to direct sunlight throughout the day, this will often make it a worthwile investment.
You can read a bit more about the different material options for enclosures in this article on machinebuilding.net.
Of course, I’ll be happy to chat to you about your specific application to help you weight up the benefits of each material before making your specification.
If you want to have a look at the Spelsberg range of polycarbonate or polystyrene enclosures then you can use the product finder to filter by material type.