Simge,
Looking at your plots, it seems that the eQUEST fan is simply larger by 40% or so. Are you letting the programs autosize the equipment, and did you use any sizing-factors or sizing-ratios in the runs? I would just take the larger
capacity of the two runs, and use that for both runs, which should take care of the discrepancy.
Other observations:
1. eQUEST CYCLE-ON-ANY seems to keep the fans on the entire hour, whereas EnergyPlus seems to cycling them on
only when the HVAC is on.
2. You seem to have daylight savings in the eQUEST, but not in the EnergyPlus model.
Joe
Joe Huang White Box Technologies, Inc. 346 Rheem Blvd., Suite 108D Moraga CA 94556 yjhuang@xxxxxxxxxxxxxxxxxxxxxxxx http://weather.whiteboxtechnologies.com for simulation-ready weather data (o) (925)388-0265 (c) (510)928-2683 "building energy simulations at your fingertips"
On 2/13/2014 8:05 AM, Simge Andolsun wrote:
Dear EnergyPlus users,
We have modeled a test case with exactly same inputs in eQUEST and EnergyPlus to compare the results of these programs for an identical situation. This case had a PTAC system with electric heating. The fan inputs were as follows in both eQUEST and EnergyPlus:· 0.3 inWG (74.7 Pa), 0.6 total efficiency fraction· In eQUEST: Fan control is constant volume, with night time cycling
In EnergyPlus: Fan control is constant volume (fan control schedule=1) when the fans are scheduled to be on and it is cycling (fan control schedule=0) when the fans are scheduled to be off (Please let me know whether there is any better way to model the same fan control condition in eQUEST and EnergyPlus).· California Title 24 fan schedules were used in both programs.These schedules turn the fan off during the hours listed below:Weekdays: Between 8pm-5amSaturday: Between 3pm-5amSundays and Holidays: Off all day.The fan energy consumption of the two programs ended up differing from each other significantly. Attached are the charts that show the results of the coldest and warmest days. Would you let me know what might be the reason for this difference between the two programs?
Thank you very much in advance for your help,
Best Regards,
S. Andolsun, Ph.D.
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