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Passive heat from building operations 2

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mguardian

Mechanical
Nov 16, 2012
5
Hi Everyone,

This is my first thread on eng-tips. I am hoping one of you can point me in the right direction here.

I am putting together savings calculations for various energy conservation measures. I am working on a calc in which i need information on the passive heat (latent heat) given off by building occupants and other heat generation outside of a buildings hvac system.

Where can i find this information on a btu/h*ft^2 basis? I need this information for manufacturing facilities, schools, office buildings etc. As many different types of buildings as i can get would be great.

Thanks in advance.
 
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ashrae fundamentals handbook is reference source for heat gains, while in ashrae systems and applications handbook you can find values, for instance, expected density of occupancy in schools, auditoriums, but you need to make final judgment.

google engineering toolbox, you can find lot of useful data there.
 
Look at RMI.org for modeling tools.

Attached is the Cal Title 24 alternative calcs manual, there is a nice table in section 2 for what you seek. It also contains a lot of good energy modeling information.

If I get a chance, I'll post some more resources for you in this thread. I have an extensive library, but not a lot of time today.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies
 
 http://files.engineering.com/getfile.aspx?folder=c83344e6-5004-4db6-bf90-803d8945fb4b&file=Alternative_Calc_Manual.pdf
I just now had to open this one (I'm working on a disturbingly complex building energy model in eQuest). Thought I'd upload it for you quick. Open only in Adobe, not an off-brand of pdf reader. Look at Appendix B first, but study the whole thing. You'll be glad you did.

Oh, and it's a freebie. is where I got it.

Others: NREL, DOE, PNNL

More next week.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies
 
Thank you all for the help.

I will take a look at what you guys posted up for me. Much appreciated!
 
This maybe a stupid question. But it is friday.

In that appendix B from COMNET, it lists the btu/occupant. How do you translate that to a rate over time.

As an example, it lists for Dining General, 275 btu/occ.
 
if you want to accurate in your calculation you do not have to estimate loads based on Btu/H per ft2, this is called rules of thumb, each project has its own specification, you could use cfm per ft2 for ventilation but not Btu/hr, it is not an accurate calculation.
for exapmle what if someone told you: it is between 10 to 20 Btu/hr.ft2, the other told you it betwwen 15 to 25 btu/hr.ft2
 
Ok BTUH makes a lot more sense.

317069, i understand these are just rules of thumb, and are not concrete rates. Do you have a suggestion on how to improve the accuracy of these estimations? Or is it something that just comes with experience?
 
The base is a references such ASHRAE or similar, the experoance is important too but each project has its own situation
 
I agree. I am developing savings calculations to use during/after an energy audit. I need base reference numbers to start with. Once a building has been walked, i can make adjustments as i see fit.

I appreciate all of the responses, and help i have gotten.

It looks like eng-tips will be a great resource for me.

Thank you all.
 
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