On Wed, Feb 7, 2018 at 6:50 AM, Tilek Aberra tilek.aberra@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Hi Jim,I am using a "dry cooler", and with tighter condenser approach temperature difference the E+ simulation predicts the outgoing water from the fluid cooler is colder than the outdoor ambient - which indicates the simulation has some issues.. I think what is happening is the outdoor temperature is increasing at a higher rate than the plant loop is responding. Also note, I am using the fluid cooler as a condenser water. What I am curious is whether the anomaly is coming from a numerical error or an actual physical limitation of the plant loop. For me partly it appears to be a numerical issue because the hours per year these anomalies occur reduces significantly when I use higher timestep. But if the anomalies are due to physical limitations, then I may explore ways to tackle the extremely hot days, either using a cheaper water spray method, or a more expensive (I suppose so) evaporative cooler as you suggested.Regards,TilekOn Wed, Feb 7, 2018 at 10:30 PM, Jim Dirkes jim@buildingperformanceteam.com [EnergyPlus_Support] <EnergyPlus_Support@yahoogroups.com > wrote:  If you are using an evaporative fluid cooler, which would be common in a very hot climate, then the water temperature can approach the wetbulb temperature. This is normally substantially cooler in the outdoor air dry bulb temperature.On Wed, Feb 7, 2018 at 05:59 Tilek Aberra tilek.aberra@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@yahoogroups.com > wrote:ÂHi Carlos,I already noted that. I was looking for some workaround using EMS or similar to override the default [which is MAX 60] if anyone has done similar exercise before.Thanks for the response though.TilekOn Wed, Feb 7, 2018 at 9:52 PM, Carlos Krebs clmkrebs@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@yahoogroups.com > wrote:ÂDear Tilek,
According to the Input/Output Reference Guide of E+, the number of timesteps (X) per hour will be between thresholds 1 â?¤ X â?¤ 60. You could see this in the IDF Editor with any IDF file opened, in the initial group "Simulation Parameters", in the class list "Timestep". There is a further explanation on screen field for this.Regards,Carlos Krebs+46 769-058-292MA. Arch. PROGRAU/FAUrb/UFPELLEED® Accredited ProfessionalInternal Auditor ISO 14.001Buildingsâ?? Energy Efficiency ConsultantOn Feb 7, 2018, at 9:36 AM, tilek.aberra@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@yahoogroups.com > wrote:Hi, Colleagues,
Can anyone suggest a workaround to run E+ with a timestep larger than 60 (the maximum acceptable)? Let say 120 (i.e. time integration at 1/2 minutes interval). I am currently running a simulation that has a "fluid cooler" object and for the very hot days, I get an erroneous water temperature leaving the fluid cooler that is less than the outdoor temperature. The number of such anomalies greatly reduces with higher time resolution (for one case 500hr/yr with timestep=6 to 0.75hr/yr with timestep=60).. I was trying to get rid of all this erroneous output.
Regards,
TilekÂ
--Tilek Aberra,
12 Bainton Pl., Doonside,
Sydney, Australia
ph:Â Â +61 (0)2 9534 4731 (home)
     +61 (0)2 8805 0421 (office)
mo: +61 (0)4 3959 5937--James V Dirkes II, CEO / President
The Building Performance Team Inc.
1631 Acacia Dr, Grand Rapids, MI 49504(alphabet soup of efforts for greater understanding: PE, BEMP, BCxP, LEED AP)
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Coffee conversation: The first idea is the worst, but it is the most important because it starts discussion and becomes the building block for other ideas.
--Tilek Aberra,
12 Bainton Pl., Doonside,
Sydney, Australia
ph:Â Â +61 (0)2 9534 4731 (home)
     +61 (0)2 8805 0421 (office)
mo: +61 (0)4 3959 5937--James V Dirkes II, CEO / President
The Building Performance Team Inc.
1631 Acacia Dr, Grand Rapids, MI 49504(alphabet soup of efforts for greater understanding: PE, BEMP, BCxP, LEED AP)
Direct / Mobile: 616.450.8653
jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx
Website l  LinkedIn
Coffee conversation: The first idea is the worst, but it is the most important because it starts discussion and becomes the building block for other ideas.
__._,_.___
Posted by: Jim Dirkes <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
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