We have sensors in our datacenters that report, among other things, humidity.
One data center is exceeding the predefined humidity alerts of the devices, but given that cisco says the operating humidty of routers is 10% to 85%, I dont know if humidity of, say, 65% is anything to worry about.
Anyone know if increased humidity correlates with decreased MTBF?
And reasonable thresholds that I can tolerate, and when I should complain to the datacenter operators? (References I can point to would be nice.)
Thanks
and when I should
complain to the datacenter operators? (References I can point to would
be nice.)
When your equipment starts to rust 
I don't have any technical references, but I think that anything over
65% is probably too much. Most facilities I have equipment in do not
exceed that mark.
Todd
IIRC, too low a humidity level makes static electricity a problem. Too high makes the cold air condense on your equipment. 60-65% sounds about right.
Todd Mitchell - lists wrote:
depends what's in your SLA. If it states 40-65%, and you notice it's
over 68% or so, you SHOULD complain. Otherwise, you "agree" to the
higher %, if they can prove you know about the higher %. (IANAL)...
Of course, there's a difference between complaining, and demanding
refund. However, I think it's wise to complain...
Kind Regards,
Frank Louwers
For a datacenter with a single controlled area the ideal range for relative
humidity (RH) is in the neighborhood of 35% to 50%.
Here are some data points:
1) Static electricity is minimized when RH is at or above 35%.
2) RH below 25% can cause embrittlement of hygroscopic materials
such as paper.
3) RH above 65% can cause mold growth and metal corrosion.
4) Humans are most comfortable when the RH is between 20% and 60%.
5) RH above 50% in cold weather can cause condensation inside of
outer�walls (or on equipment itself if the facility has an
external door or window that opens directly into the controlled
area).
Sean Donelan wrote an informative post on a related subject a few year back:
<http://www.cctec.com/maillists/nanog/historical/9810/msg00276.html>
-Richard
Todd Mitchell - lists wrote:
> and when I should
> complain to the datacenter operators? (References I can point to would
> be nice.)
When your equipment starts to rust
I don't have any technical references, but I think that anything over
65% is probably too much. Most facilities I have equipment in do not
exceed that mark.
It isn't a *huge* issue (within reason) unless you have printers around and the inherent paper. Big lasers are notoriously finicky about humidity, which directly affects the paper quality.
Otherwise, just keep it well below the dewpoint 
Jeff
Todd Mitchell - lists wrote:
> > and when I should
> > complain to the datacenter operators? (References I can point to would
> > be nice.)
>
> When your equipment starts to rust
>
> I don't have any technical references, but I think that anything over
> 65% is probably too much. Most facilities I have equipment in do not
> exceed that mark.
It isn't a *huge* issue (within reason) unless you have printers around
and the inherent paper. Big lasers are notoriously finicky about
humidity, which directly affects the paper quality.
If you are running lots of mag tape, humidity > 60 % starts to really
increase tape and head wear. If new tape heads are part of your
regular operating budget, I would keep the humidity < 50 %.
Regards
Marshall Eubanks