How can I determine what the real power demand is ? Enter the real equipment efficiency.
Regarding sizing, you can use the sizing parameters object to set an averaging window for sizing. This will average out the startup peaks you see yet still meet the load. In the example below, try using 4, 8, and 12 timesteps for the averaging window (1, 2, and 3 hours) to see what impact that has on sizing and hours set point not met.
Timestep,4;
Sizing:Parameters,
1.0, !- Heating Sizing Factor
1.0, !- Cooling Sizing Factor
; !- Timesteps in Averaging Window
I usually simulate a building with a 100% efficient boiler and chiller.
If I use autosize for the capacity of the boiler or chiller, the capacity is sometimes to low.
If I fill in the capacity manually, .... I can fill in what I want.
How can I determine what the real power demand is ?
Especially for capacity peaks at startup (morning for heating, afternoon for cooling) the manually choosen capacity, will influence the duration of the startup peak.
This leads to discussion with my client ofcourse. the software is intended to determine the peak load, but I can choose it myself....
Sometimes these peaks are also extremely high and short in duration. Is there a limiting aspect I maybe have forgotten ? (pump , or other part of the heating/cooling loop)
Geert
-- Richard Raustad Senior Research Engineer Florida Solar Energy Center 1679 Clearlake Road Cocoa, FL 32922 Ph: (321)638-1454 http://www.fsec.ucf.edu/en/ Electric Vehicle Transportation Center http://evtc.fsec.ucf.edu/
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Posted by: Richard Raustad <rraustad@xxxxxxxxxxxx>
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