I know that many server rooms are tightly climate controlled. But just how sensitive are servers (and hence all computing equipment) to humidity? Do they suffer from high or low conditions?

The air conditioning system of server rooms are generally designed for 22 degrees C (71.6 degrees F) and 45 percent relative humidity at altitudes up to 2150 m (7000 ft.) which is recommended ( source; server specifications IBM) . Also they have high tech control system which are set to high or low alarm for warning and monitored with continuous recording device with the appropriate limits marked.

Many places will setup alarms just to be the on safe side. The last thing you want to do is have all your eggs in one basket and then fry them all on accident. I know someone that did this with a home server in a room smaller than most home baths are and it ended up being so warm it literally baked everything.

I must say I do like being in a datacenter with controlled humidity. Being in Florida with 100% humidity that is a serious issue. Copper clad boards and humidity do not mix well becuase you have electrolytic reactions or corosion. And when you spend $100,000 on a single server you want it as safe as possible.

In dry enviorments you get static discharge from people that can wipe out anything. You can even get static discharge from fans or motors in the servers.

But lets face it, 99% of the servers out there are standard desktops in a rack case. How many homes and offices have climatic controls?

I have an old quad xeon in my house server room and my climate control is opening the window when its hot and closing it when its cold or rain is comming in. The server has been running for over 2 years without any problems pushing out thousands of pages a day.

I like to think the money I pay in the datacenter is worth it. But I don't think it is as big a concern for most people as people think.