[BLDG-SIM] why is energy simulation better?

[John Aulbach]

Dear Sir:

May I say it is nice to converse with an individual in
your country able to speak freely? I am glad to see we
are now able to openly discuss things with individuals
in your area of the world once again.

As a side note, one of my best friends and colleagues
(and a fellow simulation engineer) graduated from the
University of Baghdad.

My short take from 25 years of modeling experience is
as follows:

1) Models usually remember things that spreadsheets
don't. As much effort as goes into spreadsheets, a
model usually remembers to add or subtract energy use
when changing from a baseline to Energy Conservation
Measures (ECMs). Simplistic case - when lighting
efficiency is improved, it adjusts the cooling load
down and the heating load up.

2) Models allow for more dynamics than a straight
calculation. Especially with those using 8,760 hours
of simulation, they account for building usage change,
weather change, control system changes SIMULTANEOUSLY.
Once you have built your model building, and given it
instructions how to operate, any ECM modification will
automatically be affected by any and all systems
affected by that change.

3) You can try more than one way to improve the
building's and/or systems efficiency with a model.
Assume you have a new building and you wish to
investigate if a distribute packaged HVAC or a central
plant system will be the best "bang for the buck".
Once your building model is created, you can run
either system through its paces, and compare the
operating costs of each.

4) Modeling allows building orientation changes,
window/wall system changes, system changes, central
versus distributed plant changes, and even
cogeneration/thermal storage/gas-electric options to
be evaluated on a "level playing field". And a good
simulation program will remember to add components to
systems you may forget (pumps, crankcase heaters, and
the like).

5) For MY money, models are usually easier to follow
that massive spreadsheet calculation. Model inputs are
logically ordered, so one can see what the inputs are
clearly. And they don't have to be all on one page.

Spreadsheets usually have hidden formulae and take
information from several other spreadsheets. You
REALLY have to follow the bouncing ball to keep up
with spreadsheet logic.

So that is my two cents...


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

======================================================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM