At 04:43 PM 8/19/99 -0700, you wrote:
>On 17 Aug 99, at 13:14, Donald Gaither wrote:
>
> >   I just had a user ask me a question I've never had to deal with.  Will
> > high humidity mess up a computer.  He just moved a computer to his basement
> > which he said runs 100% humidity without his dehumidifier running and
> > 80-85% with it running.  He made it sound to me that he does run the
> > dehumidifier all the time.  What long term effects could this lead to?
>
>   While many components in a PC produce heat while operating, some try to
>produce cooling -- and the system probably won't be on all the time.  In high
>humidity, that's going to lead to condensation, which could have several
>adverse effects:
>
>1.  Short circuit....
>
>2.  Corrosion....
>
>3.  Evaporative cooling -- which could lead to differential expansion
>stresses and possibly cracking....
>
>   Just as manufacturers of CPUs and other semiconductors rate them for
>operating and storage temperature ranges, they also rate them for humidity
>ranges -- and it seems to me that 80% is a pretty common maximum.
>
>
>David G

Just to add to David's excellent comments:  Having worked in the HVAC field
for many years now as my full-time forte, I must say that a dehumidifier
that is only removing 15%-20% relative humidity is doing an extremely poor
job.  This is either due to under-sizing or the pure failure of the equipment.

Most likely your friend has a small room-type unit (i.e., bedroom unit) and
is trying to dehumidify the entire basement with it.

Since this obviously is not computer related (except to the extent of
damaging components), if you would like to know more, please feel free to
email me privately.  And no, I am not a salesman but I can give you some
good friendly advice.

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