[TRNSYS-users] Type 16 with DST

[Michaël Kummert]

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