I think you are confused by 3 different problems: 1) Values in an EPW file are instantaneous or averaged depending on the variable. There is some info on the EnergyPlys website(http://apps1.eere.energy.gov/buildings/energyplus/weatherdata_format.cfm). Unfortunately I haven’t found a completely up-to-date, easy to read format definition, which seems strange for a format that wants to be (and has become) a standard. I found better documentation for the TMY3 format, which I think would be useful to you: www.nrel.gov/docs/fy08osti/43156.pdf. In short, the value on a given line for temperature is the instantaneous value at that time (e.g. the 1st line has the temperature at 1 AM on January 1st). Radiation values are integrated over the previous hour, so that the 1st line gives the total radiation (in Wh/m²) over the hour between 0 AM and 1 AM on January 1st). Since the time step in these file is 1 h you can also understand radiation numbers as average values in W/m². 2) TRNSYS uses average values for ALL variables. “TIME” in TRNSYS always refers to the end of the time step and all variables are averaged over that time step. So if Type 15 reads the temperature during an hourly simulation, the value it should output for other components is not the value that it reads but the average between the line that corresponds to the current time (end of time step) and the line before. In doing that TRNSYS is not really interpolating but rather calculating the average over the time step. 3) Solar radiation projections are typically performed with sun angle values corresponding to the middle of the time step. This is what TRNSYS does (unless sunrise/sunset takes place during the time step). So during an hourly simulation solar radiation is not interpolated or shifted, but sun angles are calculated at the middle of the time step (and since TIME represents the end of the time step, the middle of the time step is half an hour before). In the case of shorter time steps TRNSYS does interpolate weather data, and it does it differently for radiation than other variables. But this email is getting too long already… Michaël Kummert Polytechnique Montréal From: trnsys-users-bounces@cae.wisc.edu [mailto:trnsys-users-bounces@cae.wisc.edu] On Behalf Of saleh saadi Dear Users, For those of you who usesTYPE15 (for EPW weather data) in TRNSYS 16. Does TYPE 15 shift the solar radiation to the middle of the hour when interpolation is performed? or uses the weather data by the end of an hour and linearly perform the interpolation? Thnaks, Saleh From: saleh saadi <salehsnjsaadi404@yahoo.com> Thanks Waseem, It is not about a specific weather file. I'm developing my own weather model reader and processor in Simulink. I have used results from E+ to verify my model but seems to be off at some times . So, I used TRNSYS _16, TYPE 15 to determine the solar radiation on south vertical surface using Perez model and compared that to my Simulink and E+ results. I figured that TYPE 15 interpolates the weather file (even at 1 hour time step) and therefore can't use it for verification. I was expecting that TYPE15 will read the weather file without interpolation when time step is 1 hr. Is there a way with this type or others to get the values at the beginning (or end ) of each hour rather than interpolating values at the mid of the hour? Thanks, Saleh From: waseem khan <waseemshahkhan@gmail.com> Dear saleh saadi, Salam, Please let me know the weather file name ? On Wed, Oct 17, 2012 at 1:52 PM, <trnsys-users-request@cae.wisc.edu> wrote: Send TRNSYS-users mailing list submissions to Dear user, I'm trying to extract some weather data from TRNSYS -16 after reading and processing EPW file using Pereze model (time step 1 hr). I have noticed that this TYPE interpolates the variables including the air temperature. Is there a way to extract the data without interpolation using this type or others? regards, Saleh ALSaadi
Dear Wang, 1) I use TRNSYS 16, there is no TSGRD in TYPE 56. 2) The height over sea level of Default is 0 m I used. 3) You are right. I tried to use *.tm2 weather data, this Error disappeared! As I mentioned previous, there must be an error in your data file. Link the outputs to the online/printer for checking 4) Yes, The data reader Type 9 is placed after the building now for my simulation., For a successive method all input data types should be placed at the beginning. Check the component order and rearrange it. Marion Dipl.-Ing. Marion Hiller Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst, Prof. Dipl.-Ing. Bleicher Von: 王洋 [mailto:wanghongyang1767@gmail.com] Dear Marion, 2012/10/10 hotline <hotline@transsolar.com> Dear Wang, there are several issues within your simulation concerning the outside longwave exchange of external surfaces 1.) You didn’t connect TSGRD such that it is set 0 => If you have no information set it Tamb 2.) For Sky temperature calculation with Type 69, you forgot to enter the height above sea level. 3.) You read the ambient temperature and the relative air humditiy from a userdefined file by type 9 4.) In addition, please check the component order. The data reader Type 9 is placed after the building. Marion Von: 王洋 [mailto:wanghongyang1767@gmail.com] Dear Marion and TRNSYS Users, ---------- Forwarded message ---------- Wang, This problem may occur from incorrect ambient condition settings: Please check the following inputs of Type 56 1- TAMB 2- RELHUMAMB 3- TSKY 4- TSGRD In addition make sure that in the BUI file the surface - outside emissitive is ≤ 1 - outside convective heat transfer coefficient ist set to reasonable value If the error presits, we need the complete project to give further advice. Marion 2012/9/28 <trnsys-users-request@cae.wisc.edu> Send TRNSYS-users mailing list submissions to Karol, I noticed from your listing (*.lst) file that your working directory is located on your computer's desktop directory. This is not recommended due to the potential issues with the Windows OS system and write privleges. I would first try changing your working directory to the ".\MyProjects" directory or in a folder right on the "C:" drive. I am not certain that this is the issue with the TRNEXE, but if the problem persists, please contact your distributor, techsupport@tess-inc.com. Best regards,
On 2012-09-27 03:46, Karol Bandurski wrote:
Karol, In general the notice has nothing to do with a frozen TRNEXE.exe, it is just an information. The message indicates that the internal controller for turning on the integrated heating/cooling has convergence problems and a deadband is applied to promote convergence. This may be the case at the moment of turning ON or OFF something. After 6 internal iterations a deadband is added to promote convergence. If the convergence isn’t reached after 12 iterations a warning is written to the lst/log file. Regards, Marion Dipl.-Ing. Marion Hiller Geschäftsführer: Dipl.Ing. Matthias Schuler, Dipl.Ing. Thomas Auer, Dipl.Phys. Stefan Holst, Prof. Dipl.-Ing. Bleicher Von: Karol Bandurski [mailto:karol.bandurski@put.poznan.pl] Dear All, I try to simulate dwelling with natural ventilation. I set some algorithm for window opening and ideal heating for colder part of year for each zone with set temperature depending on time of day. When I run my yearly simulation it stop in one moment and TRNEXE is frozen... There is even no error! Then I can only turn off TRNEXE. Only think what appear (many times) in .lst file is Notice: More than 6 iterations for internal regulation HEATING/COOLING. I will be grateful for any advice! I enclose .lst file. Regards, ------------------------------------------------ Karol Bandurski MSc. Poznan University of Technology
Wang, This problem may occur from incorrect ambient condition settings: Please check the following inputs of Type 56 1- TAMB 2- RELHUMAMB 3- TSKY 4- TSGRD In addition make sure that in the BUI file the surface - outside emissitive is ≤ 1 - outside convective heat transfer coefficient ist set to reasonable value If the error presits, we need the complete project to give further advice. Marion Von: 王洋 [mailto:wanghongyang1767@gmail.com] Dear all, 2012/9/27 <trnsys-users-request@cae.wisc.edu> Send TRNSYS-users mailing list submissions to TERI University is currently inviting applications for Doctoral programmes in Bioresources/Biotechnology;Natural Resource Management, Energy and Environment and Regulatory and Policy studies for semester starting january 2013. A range of scholarship opportunities are also available for the students in specific areas, the details of which can be accessed through the following link. The last date for application is October 31st, 2012. The details regarding fee, eligibility and other requirements can be accessed through http://teriuniversity.ac.in/index.php?option=com_program For any further details please get in touch with Dr. Sapna A Narula, Associate Professor sapna.narula@teriuniversity.ac.in. *********************************************** Dear All, I try to simulate dwelling with natural ventilation. I set some algorithm for window opening and ideal heating for colder part of year for each zone with set temperature depending on time of day. When I run my yearly simulation it stop in one moment and TRNEXE is frozen... There is even no error! Then I can only turn off TRNEXE. Only think what appear (many times) in .lst file is Notice: More than 6 iterations for internal regulation HEATING/COOLING. I will be grateful for any advice! I enclose .lst file. Regards, ------------------------------------------------ Karol Bandurski MSc. Poznan University of Technology
-- Kind Regards,
Energy Analyst Mob:+91.9999535880 |