Andy Hall wrote in message . ..

Methinks you worry too much.

Any decent kit (i.e something that's not been cobbled up in a 3rd
party case) has a wide operating temperature, and it is the rate of
change of the ambient temperature that causes an issue, not the
actual maximum or minimum temperatures.

My firewall (Compaq Pentium 2) is in the loft with no special
insulation around it, and the projected low for tonight is -4.

I'm not worried about it. It will just get extra cooling this evening
;-)

I have had computer room air conditioning failures causing a very
steep step change in temperature (up to ~32 degrees C in 1 case) I had
3 disk failures out of an installed base of ~600 and 1 machine auto
shut down due to overtemperature out of 200 (and this was found to be
too close to adjacent kit).

Similarly I have seen machines operate at either end of their
envelopes [1] without incident.

Cheers,

Paul.

[1] Spec sheets on mine say:
5 to 35 C Operating
-20 to +60 Non Operating

I don't disagree that rate of change can have a big effect, although
high continuous temperatures do affect the failure rate of electronics
in general. For example, it is common to do accelerated tests at high
temperatures to check for failure in new designs.

This kind of testing is looking for permanent, physical, failure
modes.

Operating at too high a temperature in a loft is unlikely to do
permanent damage (unless the temp is really extreme) but will cause
malfunction.

Andrew