Re: [EnergyPlus_Support] Dry bulb temperature of weather file and output file

[Rahul Chillar <chillarrahul@xxxxxxxxx>]

hi 
another user just a week back had asked the same question, below is Mike's response to the same .
Thanks
Rahul Chillar
Grad Research Assistant
Building Systems Lab
UIUC 
 
The standard EnergyPlus weather files (epw) contain hourly data. For state
variables such as temperature and humidity, the values in the epw file are the
instantaneous measurements at 1:00 am, 2:00 am, and so on. Because EnergyPlus
uses zone time steps of less than one hour, these values are linearly
interpolated for each time step. Weather data values reported from EnergyPlus
at the Timestep frequency will match the weather file one timestep per hour on
the hour. Values reported at the Hourly frequency represent the average value
over the hour, so they will not match the instantaneous value in the weather
file. The solar radiation values in the weather file are integrated total
values for the hour, so the interpolation must be done differently. The total
radiation in [Wh/m2] is used as an average rate for the hour in [W/m2], and
this average rate is assumed to be the value at the midpoint of the hour.
Again, linear interpolation is used to determine the value for each timestep.
The reported solar values in the output will match the value in the weather
file on the half hour.



winterwizardcn <mab@xxxxxxxxxxxx> wrote:
I found the Environment Dry Bulb Temperatures in the output file are 
different then the dry bulb temperatures in the weather data. I 
noticed that when I tried to modify data in the weather file but 
didn't get the required temperature when I check the output. 

Any clues? 

Thanks



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The primary EnergyPlus web site is found at:
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The group web site is:
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