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Re: [EnergyPlus_Support] Daily Sine wave amplitude....





That "is not a sin wave" comment is quite interesting. I've just finished setting up a spreadsheet to create a design day period (CDD) as required by VDI 2078. Since e+ does not yet support a longer warm up period where you can set a different 24 hr schedule for each of the previous 14 days, I am planning on using the caveat in the norm of rerunning the CDD 14 times (but loose the credit inherently given to more massive buildings, which is the point of the CDP). The authors of the norm specify equations based on a sine function, but break it up into 3 parts based on the time of max and min temps.

On 16 Apr 2016 20:26, "Joe Huang YJHuang@xxxxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
 

I caution that Design Days are by definition atypical conditions with the daily maxima corresponding to either the 0.6% or 1% highest hourly temperatures. Furthermore, the hourly profile described below is extremely generic and applied to all locations and conditions. I don't know how you intend to use the "daily variation sine curve", but if it's to understand the average daily temperatures for each month,  I would recommend calculating the average daily max/min from the weather file or even easier from Wikipedia, and then use the ASHRAE Design Day Profile
to fill out the 24 hour values. If you want to be more location-specific, you can analyze the weather file to derive the average monthly profiles. Last comment is that the daily profiles are not sine curves.

Joe

Sent from my iPad

On Apr 16, 2016, at 9:20 AM, Jim Dirkes jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Dear Heba,
The ASHRAE 2013 Handbook of Fundamentals shows the typical daily temperature range for design days o p 14.11. I doubt that it applies to an entire year, but might be a nice starting point for your work.
Inline image 1

On Sat, Apr 16, 2016 at 12:15 PM, hassan_kamel77@xxxxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
 

Hello,

I am searching for the daily variation sine wave amplitude for a certain city.

I wonder, if it is included in the weather file !!

or, should we make some kind of equations !!

I am simulating a city, where there's high diurnal range between nighttime and daytime.

Thanks in advance,

Heba




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