I'd do it personally, and keep a mental eye on it for a whole (a few years=) to be aware if it was more contankerous than you'd expect. My home WiFi/ADSL modem router located in a non-airconditioned dining room (never under 5C never over 30C) crashes mainly one monthly and an 8 port switch maybe every 6 months.
I'd expect it to be OK if you were sensible. After all, how hot can it get in England? :-). Seriously, if it was not insulated more than minimally I'd expect heat not to be an issue short term. Long term, electrolytic capacitors will halve in lifetime per 10 C rise in operating temperature. It may not use ecaps and you'd hope none were stressed highly - so not very hot so long life.
If it had minimal but some insulation from surroundings (say plastic case that stops convection and gives own heat a very mild barrier to cross) it should take the edge of British winters. Batteries dislike sub zero temperatures usually. Probably OK for backup batteries where power is low.
I'd not expect condensation to be much more of a problem than elsewhere. If you looked in the attic and there was a glass tumbler there - would you expect it to ever be fogged with condensation. Local conditions may make that ayes but usually I'd expect no.
Yeah I know a router contains a processor etc. My point was there wouldn't be any high-power devices up there (i.e. 800 watt PC power supply on a server kicking out a load of heat). It makes sense what you say about it failing sooner, though. I guess I better find an alternative method. It might be that I put the patch panel in the loft and just route a bunch of cables down to the room below and install routers/switches etc there. – Neil Barnwell – 2013-01-25T23:02:50.367
Yes. What will basically happen is that it'll fail sooner. How soon? hard to tell. If it has temperature monitoring it might even refuse to work at some point (which is better than just slowly failing without saying anything). – Gustavo Litovsky – 2013-01-25T23:04:06.977
1@Neil Barnwell Do note that although routers have processors that heat up less, they usually have little or no cooling provisions. For example, my room temperature is right now 23.3 C and the temperature inside my router is 43.1 C. Temperature of the system on a chip will be even higher than that and it could easily go uncomfortably high in the summer. – AndrejaKo – 2013-01-25T23:06:01.047
If a router is failing due to normal house temperatures, then either it was placed wrong or it was a low-quality unit. It doesn't seem likely that the router/switch will get SO hot that they fail. So long as he mounts them in free air, and not enclosed and ideally not stacked on each other... convection should do its job, along with any fans in the router/switch. – Toby Lawrence – 2013-01-25T23:14:09.743
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We aren't talking about normal house temperature, though. We're talking about attic temperature. For example, here's a graph of temperature differences in Balerno Scotland showing temps 15C higher in the attic than the rest of the house. Depending on your specific house and location, it could be more.
– Alan Shutko – 2013-01-26T00:19:30.330Correct. I once went to an attic to lift some bags up there and it was easily 120 Fahrenheit (likely more). The circuit inside the router just doesn't have anywhere to exchange air. – Gustavo Litovsky – 2013-01-26T00:30:52.950