Estimating building Loads Before doing the 220 calcs

[ron]

I'm trying to find a reference for estimating connected and demand loads very early on in a new project based on VA/sf (or W/sf), and based on some assumptions (occupancy, electric heat, electric HWH, etc)

I've used the very abbreviated list in IEEE 241 (old Gray Book) Table 15, but would like to find something more comprehensive and if nothing else, more up to date (IEEE 241 is from 1990).

http://cursos.eie.ucr.ac.cr/claroli...MS0xOTkwLnBkZg==&cidReset=true&cidReq=IE_1071

Very often when working with an Architect for a large building, I want start the conversation with the utility company about available service sizes and capacities in the area. I often just use a rule of thumb like 20 W/sf overall for mixed use commercial, but don't have a reference to stand behind me.

Keep in mind, since this is to estimate service size, it needs to be connected load because the NEC Article 220 is very conservative with it service calculation methods. I realize the utility will have different methods (more liberal = smaller) to determine my service size, but I'm stuck with NEC calculations in the US.

Thanks

 

[steve66]

RS means has a table if that helps. Hard to read a scan, but this is from 2015.

View attachment Building loads.pdf

 

[ron]

RS means has a table if that helps. Hard to read a scan, but this is from 2015.

View attachment 18338

That is a great reference. I'm guessing that is from the Electrical book?

 

[Sahib]

That is a great reference.

It gives only connected loads and no demand loads.

 

[steve66]

Yes, its from the electrical cost book.

Sahib:

I believe those are demand loads, possible taken from utility meter data. That would be the loads contractors would be interested in when doing an estimate.

 

[ron]

Yes, its from the electrical cost book.

I ran to my latest (2012 ) and it doesn't seem to have that table, so thanks for posting it.