Mission impossible

[mikehughes8]

I am in Afghanistan and have been asked to do load assessments on all the buildings on (7) FOBs that haven't been built yet. The purpose is to size generators for a building or group of buildings as appropriate. I have a drawing for some of buildings giving me the square footage. There are absolutely no electrical plans. I can figure out lighting and receptacle requirements. However, I cannot determine HVAC sizes which will account for a majority of my load. Special equipment....forget about it.

Does anyone have a good reference on how to size HVAC units based on square footage?

Thanks in advance

 

[Rockyd]

Hat off to you sir for doing what your doing. I'm not in Afghanistan, but can give you a rule of thumb for the Las Vegas/ desert area (Temps exceed 120 in the summer) If it's in a really hot spot (attic) figure a ton per 400 square foot, to 450 foot per ton (normal area).

Good luck on your project.

Edit to cover residential application.

 

[bob]

I have a drawing for some of buildings giving me the square footage. There are absolutely no electrical plans. I can figure out lighting and receptacle requirements. However, I cannot determine HVAC sizes which will account for a majority of my load. Special equipment....forget about it.

Does anyone have a good reference on how to size HVAC units based on square footage?

Thanks in advance

Mike
That is a mission impossible. Lots of variables involved. I lived on the gulf coast 3000 sq ft and had a 4 ton unit. I had the place well insulated and that make a big difference. Try these sites for more information. You may have to sign in on the first one. I am sure they will be happy to help. Give the temp and insulation info.

http://www.eng-tips.com/threadminder.cfm?pid=391

http://cr4.globalspec.com/forum/mechanical-engineering

Call back if we can do any thing else and thanks for what you do.

Bob

 

[mikehughes8]

I appreciate the comments and the assistance.
I think what I am going to do is walk around the base I am at and try to find comparable buildings and go with those size units. From there...(lighting & receptacles) I'll just calculate them at 100% demand.
There are several buildings designated as Maintenace buildings. If I add 3000VA per building that might account for a couple of welders or other specialty tools.
I'll have to use 5000VA for places I suspect there should be a water heaters or dryers etc. since I won't have nameplate ratings.
I don't think the NEC had military field operations in mind when Article 220 was written. I wish there was a standard. It would sure make it easier to justify my numbers. Perhaps somebody much smarter than me could develop that as a proposed addition for 2011:roll: