Re: [EnergyPlus_Support] simulation settings to shorten the run time

["Ipek Gursel Dino ipekgursel@xxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx>]

I actually am calculating the yearly energy use now, instead of the 4 dates that I mentioned above. So need to change some more settings. The ones I tried are: 

1. changing the timestep from 2 to 1

2. max. HVAC iterations is reduced from 20 to 5 (but did not make much difference)

3. minimum system timestep is 0, instead of 1

So instead of shading with fins, I might use overhangs. Also the zone schedules might make a difference maybe, but I havent tried anything yet. Any ideas??

On Wed, Jan 28, 2015 at 4:39 PM, dru.crawley@xxxxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Those 4 months may not be the peak months for temps or solar. The design data provided with most weather files (.DDY) includes the hottest and coldest month ? the months used for the design conditions are the hottest and coldest:

 

 

! Washington Dc Dulles IntL Ar_VA_USA Annual Heating 99.6%, MaxDB=-11.8°C

SizingPeriod:DesignDay,

  Washington Dc Dulles IntL Ar Ann Htg 99.6% Condns DB,     !- Name

          1,      !- Month

         21,      !- Day of Month

?.

 

! Washington Dc Dulles IntL Ar Annual Cooling Design Conditions Wind Speed=4m/s Wind Dir=290

! Hottest Month=JUL

! Washington Dc Dulles IntL Ar_VA_USA Annual Cooling (DB=>MWB) .4%, MaxDB=34.1°C MWB=23.9°C

SizingPeriod:DesignDay,

  Washington Dc Dulles IntL Ar Ann Clg .4% Condns DB=>MWB,     !- Name

          7,      !- Month

         21,      !- Day of Month

?.

 

You can find the hottest and coldest month in the CSV file included with the install:  C:\EnergyPlusV8-2-0\PreProcess\WeatherConverter\ ASHRAE_2013_Yearly_DesignConditions.csv  (these are the same data as the 2013 ASHRAE Fundamentals Chapter 14 Climatic Data Information).

 

Column N has the â??ColdestMonthâ?? and column AD has the â??HottestMonthâ??.

 

 

 

 

 

From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx]
Sent: Wednesday, January 28, 2015 9:00 AM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] simulation settings to shorten the run time

 

 

Create 4 different RunPeriods, one for each of the days you mention - something like this:

 

On Sat, Jan 24, 2015 at 7:13 AM, ipekgursel@xxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Hi,

 

I am linking EnergyPlus (and Radiance) to an evolutionary optimization tool that I am developing. To be able to generate and evaluate many design alternatives, I need to significantly shorten the simulation run time. The 4 calculations I am doing are heating load (21 dec.), cooling load (21 june), and lighting load (21 mar and 23 sep). what are the simulation settings that I can change? 

I already simplified the model as much as I can. My question is only about the simulation...

 

thanks in advance!!!

 

--

James V Dirkes II, PE, BEMP, LEED AP
CEO/President
The Building Performance Team Inc.
1631 Acacia Dr, GR, Mi 49504

Direct: 616.450.8653
jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx

Website l  LinkedIn

The truth is like a lion; you donâ??t have to defend it. Let it loose; it will defend itself.

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Posted by: Ipek Gursel Dino <ipekgursel@xxxxxxxxx>

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