First, some big news. We are getting ready to announce a new Open Forum. This time we will be covering cooling issues. So mark your calendars for March 19th. Check back in the space for more details or check at the group's LinkedIn Forum.That LinkedIn group has also generated some comments to the questions I posted last week. Let me know what you think.One of my analyst contacts at IDEAS International posted an article on this subject earlier in the year. His argument is that it's cost-effective to leave air conditioners off, and simply open the windows (provided you have a brick-and-mortar set up). This is especially true if you periodically swap out servers with newer, faster models anyway (~ 5 years), as the damage incurred from higher temperatures is negligible over the short-term. This doesn't answer your questions directly, but it is an interesting piece that I thought you'd appreciate. Here's the link for reference: http://ideasint.blogs.com/ideasinsights/2008/02/datacenter-too.html Forrest Carman Director of Public Relations at Literacy Bridge Supporting the statements for Forrest above: I've seen a study done by one of the big computer companies (I'll avoid giving a name, to avoid liability). The conclusion of their experiment was (my paraphrase) that running the compute equipment without anything to alter the air quality (no AC/ no humidification) did not have a tremendous effect on the compute equipment. I have a hard time believing this (maybe this is due to a feeling of self importance), and I am skeptical of the entire process, but I am interested to see it investigated further. Keith Berlin ITS Data Center Architect at UC Santa Cruz