[EnergyPlus_Support] Re: Heating degree days and cooling degree days

["rahmiandarini" <rahmiandarini@xxxxxxxxxxx>]

Thanks Drury, 

I mean that, when you compare between the DRYCOLD.EPW and DRYCLOD.TMY, did you also find the differences of heating degree days and cooling degree days?

Rahmi 

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Crawley, Drury" <Drury.Crawley@...> wrote:
>
> Heating and cooling degree days are a measure of the climate conditions.  And yes you should get the same results from DesignBuilder and EnergyPlus.  DesignBuilder uses EnergyPlus as its simulation engine.
> 
> ________________________________
> 
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of rahmiandarini
> Sent: Friday, October 23, 2009 2:05 AM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Subject: [EnergyPlus_Support] Re: Heating degree days and cooling degree days
> 
> 
>   
> 
> 
> Thanks Linda and Drury,
> 
> I've done the simulation using DesignBuilder,and then exported the IDF file to EnergyPlus. Both gives the same results.
> 
> When you (or other people?) did simulation of Case 600 (which is available as reference), did you also find that there are differences in the heating and cooling degree days?
> 
> Thanks.
> Rahmi
> 
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> , Linda Lawrie <linda@> wrote:
> >
> > We looked at this a long time ago. (2002? or earlier)
> > 
> > And the values from Drycold.tmy to Drycold.epw 
> > were the same. (Actually I'm thinking the 
> > original drycold.tmy might have been in English 
> > units or needed conversion for some fields -- 
> > whenever that happens, things can start to get 
> > round off errors). Or maybe not -- I do remember 
> > that the first attempt at conversion was from the 
> > tmy file to BLAST and then to EPW. That introduced some errors.
> > 
> > Later we got the original tmy file and made the conversion.
> > 
> > Don't forget that to compare results you may want 
> > to run EnergyPlus at the hour timestep rather than a 15 minute timestep.
> > 
> > At 12:05 PM 10/22/2009, Crawley, Drury wrote:
> > 
> > 
> > >The DRYCOLD.TMY should be a direct translation 
> > >to DRYCOLD.EPW. We only convert units where required, not the data.
> > >
> > >
> > >----------
> > >From: EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>  
> > >[mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> ] On Behalf Of rahmiandarini
> > >Sent: Thursday, October 22, 2009 1:54 PM
> > >To: EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> 
> > >Subject: [EnergyPlus_Support] Re: Heating degree days and cooling degree days
> > >
> > >
> > >
> > >Sorry, I forgot my next question...
> > >
> > >When there are differences between DRYCOLD.TMY 
> > >and DRYCOLD.EPW, then when I simulate CASE 600, 
> > >it means I compare the same case but different weather data?
> > >If yes, I conclude that this difference in 
> > >weather data is one of the factor that make my 
> > >results different from the reference (what's EP 
> > >developers have been done/provided in the literature)
> > >
> > >Thanks again,
> > >Rahmi
> > >
> > >--- In 
> > ><mailto:EnergyPlus_Support%40yahoogroups.com>EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> , 
> > >"rahmiandarini" <rahmiandarini@> wrote:
> > > >
> > > > OK Drury,
> > > >
> > > > Thanks a lot for this answer.
> > > > I need more clarification, the DRYCOLD.TMY is 
> > > provided also by ASHRAE, but why they put different 'base'? (18.3°C and 10°C)
> > > >
> > > > Thanks
> > > > Rahmi
> > > >
> > > > --- In 
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> , 
> > > "Crawley, Drury" <Drury.Crawley@> wrote:
> > > > >
> > > > > ASHRAE Standard 90.1 uses a base of 10C for 
> > > cooling degree days. That is often the point at 
> > > which a commercial building requires some sort 
> > > of cooling because of internal loads such as 
> > > computers or other equipment. This cooling can 
> > > be either by natural means -- natural 
> > > ventilation, economizer -- or by cooling equipment.
> > > > >
> > > > > ________________________________
> > > > >
> > > > > From: 
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>  
> > > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> ] On Behalf Of rahmiandarini
> > > > > Sent: Thursday, October 22, 2009 4:42 AM
> > > > > To: 
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> 
> > > > > Subject: [EnergyPlus_Support] Re: Heating 
> > > degree days and cooling degree days
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Yes, I know that.
> > > > > But, why, for cooling, EP uses 'base' of 10°C?
> > > > > Does it means that when the outside air 
> > > temperature is 15°C, then cooling is required??
> > > > >
> > > > > Thanks
> > > > >
> > > > > --- In 
> > > <mailto:EnergyPlus_Support%40yahoogroups.com>EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>  
> > > <mailto:EnergyPlus_Support%40yahoogroups.com> , Don Shirey <shirey@> wrote:
> > > > > >
> > > > > > Notice that the "base" is different (18.3C vs 18C vs 10C).
> > > > > >
> > > > > >
> > > > > > rahmiandarini wrote:
> > > > > > > Hi,
> > > > > > >
> > > > > > > I have question regarding weather data 
> > > of DRYCOLD.TMY, provided for simulation of case 
> > > 600, ANSI/ASHRAE Standard 140-2004.
> > > > > > > I have converted the weather so that i 
> > > can use the simulation in DesignBuilder & EnergyPlus.
> > > > > > > When I checked the documentatio of 
> > > ANSI/ASHRAE Standard, it is mentioned :
> > > > > > > Heating degree-days (Base 18.3°C) : 3636.2°C - days
> > > > > > > Cooling degree-days (Base 18.3°C) : 487.1°C - days
> > > > > > >
> > > > > > > and in the DesignBuilder
> > > > > > >
> > > > > > > Heating degree-days (Base 18°C) : 3379.2°C - days
> > > > > > > Cooling degree-days (Base 10°C) : 1446°C - days
> > > > > > >
> > > > > > > and my question is that, what does it 
> > > means, and why those values are difference as 
> > > they're originally from the same data.
> > > > > > >
> > > > > > > Thanks,
> > > > > > > Rahmi
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
> > >
> >
>




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