There is less chance of someone accidentally unplugging stuff from a locked cabinet.
Some clients will want to store things like software CDs and other items and would prefer people don't see them just sitting there or potentially being "borrowed" by other customers.
Also, if you want corporate clients most will require a locking cabinet.
Aside from the physical security that a closed rack provides, from a heat control perspective, does a closed rack with fans provide better air circulation and heat control than an open rack where heat can supposedly escape from any side? Which solution is the better solution for a 10x11 computer room without raised floors? Thanks!
I wouldn't say so. It's a 10x11 room with it's own AC intake and return. The return is directly above the rack; however, the room could get warm because the temperature is controlled by a thermostat in a separate larger room. The people in the other room aren't too excited about it feeling like a meat locker, so I would expect the temp to fluctuate as the air kicks on and off.
I think I will end up sticking with an open rack in order to allow the heat to escape better.
In cases where there is no raised floor (or when the area under the raised floor is not used as the air supply plenum), I recommend open racks. Do think about a separate AC unit for the data room though. It may be worth the expense. Typical 'people space' HVAC equipment does not control humidity. In fact, the cooling process removes moisture from the air. (That's why AC units generate condensate.) Dry air means more static electricity and static is a server killer.
Also, there are cheap temp/humidity monitors that can send emails if parameters are exceeded. You may want to consider one or more of those just so you know what's going on in your data room.
Open Rack Vs Closed Rack
