[BLDG-SIM] Hourly Report Problem.

[Albert Sitorus]

Hi all,
 
I am modeling a 31-story high rise. This building uses VAV (reverse action
thermostat type)  and two-pipe fan coil units (reverse action thermostat
type). I have tried reversed action and proportional thermostat type but
both gave me the same results. It also has a DOAS that serves 26 floors with
CFM ranging from 50 - 100 CFM. All systems are assumed to be code values.
The intention of this model is to estimate cooling load during peak
condition. I let all schedules to be the default except for lighting and
equipment schedules. These schedules are set to be always on. 
 
I ran the model and the result is 97% out of throttling range. I figured
this is because of the peak condition which the systems can't meet the
desired temperature set-points (heating 70 deg, cooling 75 deg, and 4 deg
throttling range for all systems). I ran this model and got the hourly data.
It got more interesting. From SS-D report, I gathered that on Sept 5 @ 4pm
is the peak condition for the building which is located in Portland, OR. I
pulled out hourly data for that day and plot them in excel. The curve is
nice and smooth with a couple of peaks and valleys at the beginning of the
day with a distinguished peak at 4pm. I also grabbed hourly data for winter
season. I picked 3 days ( Jan 3 is the lowest load from SS-D report). For
Jan 3rd, the curve is nice and smooth similar to Sept. 5th curve. But when I
graph Jan 6th and Jan 1st, the curves don't make sense. Both curves behave
as sinusoidal curves. They go up and down every hour of the day. I don't
understand them. Is this because of the model is out of throttling range? If
so, why on certain days and not all of them. 
 
Thank you very much for your help and suggestions in advanced. I gladly
appreciate them. 


Albert T. Sitorus
Energy Analyst
 

 <http://www.glumac.com/>  
  _____  

320 SW Washington, Suite 200
Portland, OR 97204-2640
T.  503.227.5280  F. 503.274.7674

Thinking. Inside the building.
www.glumac.com <http://www.glumac.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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20060406/5e58b264/attachment.htm>