Energy calculation for HVAC systems

AI Thread Summary
To approximate heating and cooling costs for a commercial office space, the discussion emphasizes using ASHRAE standards and computer modeling programs due to the complexity of variables involved. The participant has explored temporary gauges for energy measurement but found the costs prohibitive. Suggestions include accessing ASHRAE handbooks or consulting HVAC contractors for estimates. A specific modeling program was recommended, with a free trial available for testing. The conversation highlights the challenges of estimating energy needs without detailed data and the necessity of using advanced tools for accuracy.
MacLaddy
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I've been asked to approximate a dollar amount for heating and cooling an occupied tenant space in a commercial office building.

We've looked into installing a temporary gauge on each unit to give us a good approximation, but the cost to gauge up all the electrical and gas was beyond the scope of what I'm allowed. I even looked at just gauging up a few and approximating the rest, but that wasn't feasible either.

The only variables I can provide are square footage, head count, and a possible computer count.

Any ideas on how I can come up with a reasonable number? Any help is appreciated.

Mac

Additional Info - This space is controlled by 8 package rooftop Lennox units, varying between 3 and 7 tons.
 
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ASHRAE provides standard heating and cooling procedures for estimating heating and cooling energy balances. See if you can access any of their handbooks or technical standards at your school or company library.
www.ASHRAE.orgor get an estimate from a heating and air conditioning contractor or your local utility.
 
The only way to get a realistic estimate is to use a computer modeling program.
 
NUCENG said:
ASHRAE provides standard heating and cooling procedures for estimating heating and cooling energy balances. See if you can access any of their handbooks or technical standards at your school or company library.
www.ASHRAE.org

Thanks for the link. I'll look through it.

russ_watters said:
The only way to get a realistic estimate is to use a computer modeling program.

That's what I was afraid of. There are just too many variables to take into account.
Just curious, what kind of program could model this? I haven't delved into anything like that yet.

Mac
 
Thanks Russ! I'll give it a shot. (although I doubt I'll be able to accomplish much without training)
 

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