Friday, May 18, 2012

Why IT practises are bad for broadcast installs

I'm in the middle of a big build where (in common with lots of film and TV facility builds) we're a subsidiary to the IT department and so have space in their comms room rather than have our own MCR. There are quite a few standard practices in building IT installs that don't map nicely onto the optimal configurations for TV builds;

1. Air conditioning - I go on about this endlessly but having done this many times I have a few observations about why under-floor hot-cold isle comms room cooling isn't suitable for TV equipment (and in fact it's not really suitable for IT builds!). Nobody in IT server-room construction has ever been able to answer me any of the objections below other than this is standard practice.
  • Cold air is heavier than hot - why try and fight nature by pushing cold air upwards rather than dropping it down the front of the cabinets?
  • Raised floors leak - cable entry holes into the room and once tiles have been lifted and dropped a lot of cold air is spilling out reducing the pressure in the cold isles.
  • Lots of additional brush-covers for cable entry into the cabinets
  • Dust is forced out of the floor void (and into the equipment!).
2. Patch panel layout - I shudder when I see structured cabling panels where the eight tie-lines to a room just present sequentially with no thought to how they'll be used. It's just lazy and means no attention has been paid until an engineer is patching up. It also means bays are very untidy from the start and you see super-wide bays with cable-management down each side. Things needn't be that messy from the start.  This is a real comms room;

3. "Flood wiring" of cabinets - This one relates to the previous point, but by avoiding thinking about the room and over-spending on 'flood wiring' you see 24-port panels at the top of EVERY CABINET going back to the haystack above.

4. Power specifications - Despite every bit of equipment having a switch mode supply (and hence being an inductive load) every MCB in most mains rooms are C-rated and double the required capacity (C32s for the 16A circuits etc.) - I'm sure using correctly rated D-breakers would be better from a safety and reliability point of view. Again - it's about not taking responsibility early on; keep our options open!

All of these are a function of the fact that the clever part of IT installs is in the switches and servers. The cabling is generic (one cat6 is much like any other) and so there is little compulsion to do it as nicely as it can be.  My heart sinks when I start a job and the first thing the customer's PM says is "...this is off the back of the comms room build"! 

This is the way I like to leave things;

1 comment:

Joel Gilbert said...

That first picture is terrifying!

"Follow the yellow cable!"