It actually depends on how you pipe the ac in order to chill the room. A raised for is not a must... if you link up piping and then have air blowing from both sides of the room its just as effient as a raised floor.

Anyway, we decided to do raised flooring.

It does give the data center a better look and also sounds more professional. However, many big companies such as Internap, and Equinix don't even use Raised flooring in the data centers they have. I know the Internap one in NYC has no raised flooring and also none of the Equniix data centers have Raised Flooring.

Cooling isn't exactly the issue it was more so for the looks, and the ablity to run cables and to look cleaner. However, it will allow the data center to be in the low 50's.

You can still look professional with a raised ceiling.... All you do is have mental poles and a pop at the bottom of each pole.

raised flooring is a major fire hazard that a good dc will not allow. it also typically creates a cabling mess when somone decides to cable under the floor which eventually leads to an obstructed cabling space.

raised floor is from the old days when large main frames were designed with a hole in the bottom of htem to sit on a hole in the floor to recived their cooling from the plenum space. this is how it was done - unless of course you had a fancy water cooled mainframe like the company I used to work at had.

any way - in the hard core telco centers designed to run at 100% uptime with no hazards you will not find a shred of raised floor.

Would just like to note that the previous posts were made by the former owner of HostAffect, not me. I actually see no good use for raised flooring. Equinix has proven that raised flooring is not necessary. Simply use overhead conduits for running cable, much simpler than doing it under the floor and then a properly done overhead cooling system, as cold air falls anyway, which would make it more efficient than pushing it up through the floor.

I am actually unable to find a single advantage to raised flooring, other than the fact that that seems to be what most people expect.

There are reasons to chose the ladder rack, or cieling based system. First of all, it is cheaper, in almost all cases. Second, according to most of what I have read, cooling from above, and not the raised floor type of cooling is more efficient overall. This does make sense, as cold air falls... In addition, in most cases, running cables above the racks is an easier and more organized process than being forced to put them underneath, forcing you to lift up tiles, go around all sorts of supports, etc.

I'm not saying that you are an idiot for chosing raised flooring, if you have compared the two methods and deemed raised floors to be better for you, good. I just see no reason for it in any setup I may have.

raised flooring is a holdover from the 60's and 70's when large mainframes that required air cooling had a hole in the bottom of them and the air was pushed form under the floor and up throug the chasis. most are not designed like this any more - some are even water cooled. any way- unless you have a mainframe shop that requires it - there is no use for it - especially in most current colo environments. I have worked in many raised floor mainframe and colo environments since the mid 80's and there is no need for them now. most people just dont know any better and as karl pointed out - its the lemming effect - people just do it because they think you are asuppoed to.

in fact you get heat loss problems in raised floor because you are cooling the floor that the air is forced in direct contact iwth. not good.