Forgive if this is duplicate. Too many posts in the various forks of this thread to dig through them all.
http://www.troxaitcs.com/aitcs/products/co2_mcc/index.jsp http://www.modbs.co.uk/news/fullstory.php/aid/1735/The_next_generation_of_cooling__for_computer_rooms.html "CO2 has the additional benefit that should a leak occur, it is electrically benign. Imagine the consequences of a leak of water or refrigerant. While a leak of CO2 could be a health-and-safety hazard, the risk is minimised by CO2 detection as part of the system." > On Thu, Apr 3, 2008 at 11:58 PM, Patrick Giagnocavo <[EMAIL PROTECTED]> wrote: > > > > > First, I would like to thank everyone who responded to my initial query. > > > > It seems that power and how to remove the resulting heat, is certainly on a > > lot of people's minds. > > > > Clearly the days of "including" power are past in all but sales and > > marketing materials. > > > > There is a cost to each component and markup is applied (if internally and > > not broken out to the customer) on each rack, each power circuit, etc. with > > covering the overhead of UPS, diesel generator, chillers, etc. being a big > > priority. > > > > After some thought, I believe, to coin a term, that "DHR" or direct heat > > removal, in some fashion will be the "new" thing for the datacenter. > > > > Somewhat counter-intuitively, the focus will be to remove the heat that > > comes out the back of the rack rather than worrying so much about the > > temperature of the air going in the front as long as it falls in a > > generally acceptable range of say, 68-75F. > > > > My guess is that someone will come up with an inexpensive, reliable way to > > put a heat collector, which will basically look like a car radiator the > > size of a rear rack door, directly behind the hot air coming from the > > systems in the rack. > > > > Hot air flows past the cooling fins and is quickly cooled back to 68F; the > > heated refrigerant is immediately piped away, out of the room and to the > > chiller, so that the evil BTUs do not spread out and contaminate other > > areas of the room. > > > > It might involve a phase change material, or might involve a more > > traditional refrigerant. > > > > My money would be on R744, also known as CO2, as it is not polluting and > > can serve double duty as fire suppression (provided you have enough on hand > > to flood the area/room). > > > > Detectors for leaks are very inexpensive and the technology for the > > closed-loop of the refrigerant cycle is already here. > > > > It is not caustic the way any of the salts-based variants would be, is not > > explosive, and is heavier than regular air, meaning it will sink below the > > area that most people breathe at should there be a small leak. > > > > With the heat being removed within a few inches of where it is generated, > > less CRAC units will be needed to keep the rest of the air cooled; and > > possibly, no separate unit would be needed if enough heat can be removed to > > drop the temperature below 68F. > > > > For fire suppression, an alarm would sound and only when it can in some > > fashion be "proven" that no humans are inside the area, CO2 is flooded into > > the area and the fire goes out. Some form of ducting which mixes the CO2 > > with regular air and exhausts it is needed after the fire is out. Firemen > > go in with oxygen if they need to enter before this is done. (obviously > > there would be an entire tested procedure for how this is done, probably > > including a small oxygen mask with ~4 minutes of O2 placed beside each fire > > extinguisher and within easy reach). > > > > (For racks with less than say 4KW of power use, network and power is fed > > from overhead with a few feet of slack in the cables, as well as a portion > > of the DHR piping being flexible tubing. This allows them to be placed > > more closely together than normal, almost front to back to front to back, > > with enough slack to pulled the wheeled racks "out" from the stack so it > > can be worked on (sort of like pulling a book out of a bookshelf). They use > > far less space and are sold a little cheaper by the colo facility.) > > > > Surely there is a limit as to how much air can be moved around, even with > > the use of best practices, there are hot spots. > > > > Simple physics dictates that this is a less energy intensive cooling method > > as a) moving a lot of air around requires a lot of energy b) air is a lousy > > way to transfer heat away from where you want it to be compared to other > > materials. > > > > Cordially > > > > Patrick Giagnocavo > > [EMAIL PROTECTED] > > > >
