[TRNSYS-users] Type 16 with DST

David Bradley bradley at tess-inc.com
Wed Sep 8 07:58:06 PDT 2004


KH,
   I might add to what Michaël said by mentioning that another way of 
handling daylight savings time is to introduce an equation into your input 
file that pushes occupancy, lighting, and equipment schedules ahead by 1 
hour during the summer since the weather data doesn't really skip or repeat 
an hour, we simply follow different schedules in the summer and winter.
Kind regards,
   david

At 06:23 PM 9/7/2004, Michaël Kummert wrote:
>KH,
>>
>>I'm using TYPE 16 Radiation processor to calculate solar radiation on 
>>horizontal and vertical surfaces.
>>
>>I think total radiation on the west and east surface should be symmetric 
>>but it is not. So I guess there could be a problem handling the 
>>parameters for the Type 16 in case of DST is employed. How can I handle 
>>it when the DST is applied?
>>
>>If the location is on Daylight saving time, do I submit 15 for the SHFT 
>>like "L_st-L_loc-15" instead of "L_st-L_loc"?
>>
>
>Most of the weather files covering one year are recorded in (local) winter 
>time or in solar time for obvious reasons.
>In case you think your file is using local summer time (Daylight Savings 
>Time), you can change the "shift" parameter in Type 16. If the file is DST 
>it uses a local standard meridian that is 15 degrees "1-h ahead" of the 
>"winter" standard meridian (and remember that "1-h ahead" means -15 deg in 
>TRNSYS).
>
>Example: Madison, WI
>Longitude = 89.33 deg West, +89.33 for TRNSYS
>Madison is in the Central Standard Time (CST) time zone, i.e. UTC-6 so LST 
>= 6*15 = 90 deg
>In summer, Madison uses CDT (Central Daylight Savings Time), i.e. UTC-5 so 
>LST = 5*15 = 75 deg
>
>Thus for a standard weather file in local (winter) time, such as the US 
>TMY2 data, SHIFT = 90-89.33 = 0.66 deg
>
>For a file that would have been recorded in Daylight Savings local time, 
>SHIFT = 75-89.33 = -14.33 deg
>
>If you have such "synchronization" problems, I would (as always) suggest 
>that you plot the extraterrestrial radiation computed by TRNSYS versus the 
>measured values to see if sunrise/sunset match the data (a 1-h shift will 
>immediately show even on a short period of time).
>
>Kind regards,
>
>Michaël Kummert
>
>--
>_________________________________________________________
>
>Michaël Kummert
>
>Solar Energy Laboratory - University of Wisconsin-Madison
>1303 Engr Res Bldg, 1500 Engineering Drive
>Madison, WI 53706
>
>Tel: +1 (608) 263-1589
>Fax: +1 (608) 262-8464
>E-mail: kummert at engr.wisc.edu
>
>SEL Web Site: http://sel.me.wisc.edu
>TRNSYS Web Site: http://sel.me.wisc.edu/trnsys
>_______________________________________________
>TRNSYS-users mailing list
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