I might think far more "obsolete" than "bad idea". It worked very well for the mainframe folks.
-- Will On Tue, May 21, 2019 at 1:50 PM Jay West via cctalk <cctalk@classiccmp.org> wrote: > > No modern datacenter that I have seen still uses a raised floor *OTHER THAN* > about 3 inches for a ground plane. There is a reason for that... the old idea > of forced cooling under the floor and mixing power & data cables there has > been found to be a truly bad idea. > > Power in most any modern datacenter is via "track lighting" rails directly > over the row of racks. Ex: https://www.starlinepower.com/busway/ > > HVAC units are generally not inside the datacenter any longer either, nor are > UPS's. These cause access control issues with vendors doing maintenance and > raises issues for publicly traded companies that must meet certain control & > accountability standards. Not to mention locating them on the datacenter > floor can cause issues with cool air routing. So these days the hot and cold > aisles are alternating, with a windsock/tube above the racks for cold air > delivery to the front and an 8 foot or so fan built in the hot aisle wall. > This is the optimum place for particle (smoke) sensors as well. That design > also lets in certain situations outside air to be used. > > So to say you "definitely need a raised floor for a datacenter" is only true > if you are trying to create a period replica. A modern datacenter built that > way... well... not sure any self-respecting contractor would build one 'the > old way' :) > > J > -----Original Message----- > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Adrian > Stoness via cctalk > Sent: Tuesday, May 21, 2019 12:03 PM > To: Patrick Finnegan <p...@vax11.net>; General Discussion: On-Topic and > Off-Topic Posts <cctalk@classiccmp.org> > Subject: Re: Pleas ID this IBM system.... > > all systems have their advantages disadvantages it all depends on what your > doing and designs u choose. personaly i think raised floor and tray above are > best then u keep all ur power below away from ur data lines plus but then ur > setup is only as good as the lazyest tech u get comming in running stuff. > > On Tue, May 21, 2019 at 11:38 AM Patrick Finnegan via cctalk < > cctalk@classiccmp.org> wrote: > > > On Tue, May 21, 2019, 04:13 Christian Corti via cctalk < > > cctalk@classiccmp.org> wrote: > > > > > You definitely need a raised floor > > > for a data center. You need it for forced air cooling and for > > > running the water and condensate pipes. > > > > > > Ductwork doesn't have to be below the floor. Modern co-lo facilities > > that I have been in (such as Switch Supernap) don't have a raised floor. > > > > Plumbing (unless you're doing aisle containment or RDHx) shouldn't run > > through the IT space in the data center. > > > > Cooling water to racks should be dewpoint adjusted, so you don't need > > condensate drains inside the DC. > > > > And overhead trays are much more difficult to > > > work with if you want to lay new cables because you have to climb up > > > and down the ladder all the time, moving the ladder from here to > > > there and back to here... > > > > > > > I solved that by having multiple ladders. In my experience, it's a lot > > easier than trying to reach through a cluttered raised floor under racks. > > > > The only good reason that I have seen in this thread for a raised > > floor is to match older equipment that routes cables downwards. > > > > Pat > > > > > > > > >
