Design watts per sq ft

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S Arle

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Would anyone be able to point me to a source where I can find rule of thumbs for watts per square foot, based on certain building types.

I need information for when we are in the Schematic Design stage of design, I can approximate the size of the incoming service.

For example:
Watts/sq ft for a Convention Center
Watts/sq ft for a University Business School
Watts/sq ft for a Hotel Kitchen

Does Means have this info?

Also

I'm also looking for rules of thumb for electrical room(s) footprint requirement per a buildings sq ft size (ie: What size elect room for a 20,000 sq ft office bldg? What size for a 100,000 sq ft school? etc, etc)

Any help or direction to resources would be great

Thanks
 
I do some work for a management company, and they tell me that the available power from receptacles needs to be right at about 5 watts per square foot to satisfy the requirements of savvy prospective tenants.

I was bidding on a generator job for a data center with a lot of cooling and quite a few of those real hot running power hungry blade servers, and their real total load was just shy of 500 watts per square foot. Amazing.

I know none of this answers your question, but it was on my mind.
 
"Have you looked at Table 220.12?"

Yes - thats good for the lighting load, but in a 'special' building like convention centers, there is a high power load due to all the booth requirements
- And then there is HVAC load

I had resources like this where I used to work for all building types - Im searching the net, but all I find is the Lighting

mdshunk
- yes, Data Centers are another one with large requirements - One number I do remember, was that the numbers we used for design was 500 watts/sq ft
 
The table in the code book only cover lighting and a few other things - IMO it is no way to base a full service on without adding up all of the other equipment.

While I do not believe there are any rules of thumb per se for watts per foot for sizing an electrical service as there are far too many variables in the way of equipment of all kinds, lighting and end use. The only rule of thumb I could think of would be to gather all of the other rules of thumb that make up what will be an end use - and bounce them off of an Electrical Engineer... That is what they are paid to do for you.

Air handling, equipment, and lighting etc. can be so broad that no one rule could accomadate such a task.

And likewise and equipment areas should determined based on the size and type of service equipment and distribution - which is determined by load calculations based on what is installed, and 'round we go back to the begining....

Sure you could base some things on other simular buildings in simular environments sharing a simular use - but the end result would be the same - someone is going to have to crunch numbers for the specific situation - by doing a little work on the many things that will comprise the final building.

On another part of the question at hand - there are some standards for sizing telecom rooms for building based on number of work-staions etc.

ANSI/TIA/EIA-569-B

One could say you could base electrical rooms in the same way - but not always.... ;)
 
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Im talking about Schematic Design - as in, your first few weeks on a project.

As a design team (That has many engineers) we need to be able to give approximate sizes for space planning, and price estimating. - These numbers are always considered "general" and "approximate" at this early stage of the project.

Of course we refine our calculation based on the actual specified equipment during the DD and CD design phases of the project.

As I mentioned, we did this all the time where I used to work, based on historical data for various types of buildings.

I do have tel/com guidelines from ANSI/TIA/EIA, but thanks for the link.
 
mdshunk said:
I was bidding on a generator job for a data center with a lot of cooling and quite a few of those real hot running power hungry blade servers, and their real total load was just shy of 500 watts per square foot.

Amazing.
Click to expand...

Especially when you consider an awful lot of those square feet have nothing on them, they're just walkways. Its just the racks that each gobble 25KW of juice and put out 25KW of heat, all of which has to be removed, and removed sharpish. Or else :)

And you gotta hope those "power hungry blade servers" are not running "real hot"...

I've often said it; data centres are full of very expensive fan heaters. Who would ever think of making money putting fan heaters in a walk in fridge...
 
S Arle said:
Im talking about Schematic Design - as in, your first few weeks on a project.
Click to expand...

I don't have a link for a rule of thumb, but do you have an A/E engaged?
Or one you use often? They should be able to give an order of magnitude estimate. We electrical types are at the mercy of the other disciplines until they determine all the equipment they require. My expericence says take their estimate and apply ~50% more.
 
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