Emerson Network Power has issued two ebooks that cover basic facts about datacenter cooling and uninterruptible power supplies (UPSes).
Emerson Network Power has issued two ebooks that cover basic facts about datacenter cooling and uninterruptible power supplies (UPSes).The two e-books (in PDF format) are hardly the last word on the topics, and fall well short of being a guide to going green. But for an SMB facing the issue of running a data center they do seem worth the few moments it takes to read them.
The six-page "More Cooling for Less" covers heat removal ratios and how to calculate annual operating costs for data center cooling. It points out that there are two kinds of cooling: the removal of humidity, which makes you feeler cooler since your sweat can evaporate faster, and the actual lowering of the temperature.
Standard "comfort" air conditioners spend 60-70 percent of their energy lowering the temperature and the rest on lowering the humidity. But since computers don't sweat, data centers should spend more of their a/c energy on lowering the temperature through the use of "precision" coolers, the book said.
The 11-page "Avoiding Trap Doors" talks about buying uninterruptible power supplies, and says that, to cover growth, you should buy enough capacity to cover the full wattage of the machines, not just their nominal draw. It also urges the reader to make sure that their UPS system has enough backup run time, and that smaller UPS units should be consolidated into larger single units. If they add up to more than 20 kw, multiple units should be replaced with a single room-scale unit.
The book also explains the difference between "line interactive" power conditioning and the double conversion process. (The latter costs more but the batteries should run longer.)
Of course, keep in mind that Emerson Network Power makes data center coolers and UPS units, so they have an ax to grind. Still, information is information. The firm is one of the largest makers of power supplies in the world, and is a subsidiary of Emerson Electric, a $21 billion conglomerate based in St. Louis.