Electrical/Telcom Room Square Footage

[Artemis]

I am in the process of reviewing a number of typical projects to determine a percentage of square footage required for electrical room/closets and telcom rooms/closets per total square footage of building.

I often hear at the beginning of a project "how much room do you need?", then, after hearing my answer, the architect trys to reduce it. I realize the configuration of these rooms are critical in regards to working clearances, but am trying to come up with a rule of thumb.

I am curious to know if anyone else has been through this exercise and what your findings are.

 

[dahualin]

Normally I will calculate the room size based on the number and dimension of electrical equipment plus some extra space. It will not be too small or too large. Architects cannot reduce the room size without our approval.

 

[Artemis]

Thanks, dahualin. I am still trying to come up with " I need __ % of the total square footage for Electrical/Telcom rooms", purely as a rule of thumb... any takers???

 

[480sparky]

I vote 100%.

 

[Mr. Bill]

Floor plans have too many variables for a hard % number. Numbers are a little easier based on work station floor area. (Office desks) Some numbers I've seen is about 0.7% of telecomm room area per work station area. Or 1 sf per every 143 sf.

It can also be based on drop counts.
Look here on page 13, Appendix D
I recommend at least 3' in front of each rack

Manufacturers will not certify the installation if a cable length is over 300' from the telecomm room to the data drop at the desk. A lot of designers will draw a circle with a 200' radius centered on the telecomm room to approximate this distance. It provides some fluff for cable routes that twist and turn and go up and down. So building geometery or room location may increase the need for additional telecomm rooms.

Edit: Revised room sizes.

 

[e57]

Another simular break down for Tel/Data, and of the TIA-569 "Pathways and Spaces" can be found here.

Electrical would depend on a few factors... Voltage and amperage of the equipment, manufacturer and access. No real rules of thumb there, other than good planning and Artical 110.

Don't forget UPS, and other equipment either...

A while back I had a GC take it upon himself to shrink my electrical room to the size of a broom closet. When I left the job one day it was as planned - a 16'X8' room with double doors. I came back a few days later it 4'X4'. It was roughly the size of the one of four cabinets I showed up with.

 

[Mike01]

Est. Loads

Est. Loads

A lot of this depends to on what type of facility you have for example a hospital or health care facility will typically require more space due to the normal / critical / life safety and possibly equipment panels, also transfer switches etc. I have also seen where they require a seprate room for I.T. and one for BioMed equipment. For lighting it?s easier than power (I think) following the ASHRE and energy codes multiply your building sq. footage by the allowable watt per sq. ft. and a percentage for task / exam / other lighting and you should be able to figure out how many branches you need, depending on the size of the building you might want two closets depending on voltage drop etc. if you have emergency lights I have found normally in the beginning 0.25 watts per square foot for EM lighting is pretty generous, for the HVAC if you do not have a mechanical on board search the site there is a lot of information on different systems and others thoughts on watts per square foot for mechanical, and then depending if it is manufacturing, hospital, you can get a pretty good idea of a receptacle / equipment load. Is there a Kitchen, Break area (coffee, vending machines) etc.

 

[mkoloj]

You think that's bad?

You think that's bad?

Another simular break down for Tel/Data, and of the TIA-569 "Pathways and Spaces" can be found here.

Electrical would depend on a few factors... Voltage and amperage of the equipment, manufacturer and access. No real rules of thumb there, other than good planning and Artical 110.

Don't forget UPS, and other equipment either...

A while back I had a GC take it upon himself to shrink my electrical room to the size of a broom closet. When I left the job one day it was as planned - a 16'X8' room with double doors. I came back a few days later it 4'X4'. It was roughly the size of the one of four cabinets I showed up with.

Electricians have a little more clout, us tele\data guys always get shafted when it comes to space getting taken for ransome.


From E57's link:

Rule of thumb: Provide 0.75 sq. ft. (697 sq. centimeter) of equipment room
floor space for every 100 sq. ft. (9 sq. meter) of user workstation area.

I would be delighted if we got that much space during a new buildout, we usually get the same amount of space as the housekeeping closets.

One good story I heard of is a PBX room that was designed too small and a bathroom next door was donated to the cause, with the toilet included.
Imagine a PBX room with a working toilet out in the open in a corner.
There goes the "I have to go to the bathroom." escape route.

 

[LawnGuyLandSparky]

A while back I had a GC take it upon himself to shrink my electrical room to the size of a broom closet. When I left the job one day it was as planned - a 16'X8' room with double doors. I came back a few days later it 4'X4'. It was roughly the size of the one of four cabinets I showed up with.

Is it just me, or does anyone else get a little rise when a GC shoots himself in the foot?

 

[e57]

Is it just me, or does anyone else get a little rise when a GC shoots himself in the foot?

If I remember correctly, the guy asked, "What are those?!?" as they were coming off the lift gate. 'One part of the main service...' I had not even seen what he had done to the room yet, in my day or two absence he gave over the space he robbed from me to the plumber and HVAC who quickly lept on the chance for needed space. Not only did he have to re-do the walls, but evict them too after things were installed. His thinking was, as with jobs with this same person in the past, that I was in my usual battle for minimum space for a panel/load center... Even though there had been meetings where he sat there as if I were speaking chinese, they were drawn on the floor plans - even elevations were done for them....