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Re: [TRNSYS-users] Type 16 with DST
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@engr.wisc.edu
SEL Web Site: http://sel.me.wisc.edu
TRNSYS Web Site: http://sel.me.wisc.edu/trnsys