<html> <head> <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">Ida, It has been probably 10 years since I looked at the esp-r surface heat balance and transient conduction routines for the surrounding ground.  But, at that time, the answer was "no"  - it did not model the effects of snow by either changing the reflectivity of the surface or by accounting for the insulating effect of snow.  I strongly suspect this is the case for most or all other building simulation tools.  If you are only interested in getting an answer for a particular building in a particular location, you can STOP READING HERE and hope that someone else will give you some more useful advice!  But, since I am involved in related research, I have a few thoughts on the matter...and am always interested to find out that I have missed some published work in the area, don't know about an unpublished technique or method, there is a better way to do it; I am plain wrong, etc.!  Then, from my perspective, the basic issues are: (1) You need to have weather data that would support this kind of calculation.  I have looked at a lot of the EnergyPlus weather files for the USA and while there are fields for precipitation, in many cases they just have zero values.  On the other hand, I think you mentioned Östersund in an earlier message - I checked the IWEC-2 data file for Östersund and it does have precipitation depth in liquid equivalents, including values for hours that are below freezing.  With that, it would at least be possible to estimate when you have snow fall.  I suspect one reason for the paucity of freezing precipitation data is that you need a heated rain gauge to measure precipitation "correctly" in sub-freezing conditions; heating the rain gauge can introduce other errors; at least here, automated surface observation stations tend not to have heated rain gauges because of the power requirements.  That doesn't explain why there is a shortage of any precipitation data in weather files here in the USA, though. (2) From an energy calculation standpoint, a typical snowfall year is problematic for calculating heat loss from the basement or foundation.  In many locations, a year with an early snowfall will have much different ground heat transfer than a year with a late snowfall.  This seems to be highly random for many locations. (3) To automatically predict, in a building simulation tool, when you would have snow and how much snow would be present and what its insulating value would be, you would need a full snow accumulation/melting model.  We have done this for bridge deck snow melting systems: <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> Liu, X., S.J. Rees and J.D. Spitler. 2007. Modeling Snow Melting on Heated Pavement Surfaces Part I: Model Development. Journal of Applied Thermal Engineering. 27:1115-1124. <o:p></o:p> Liu, X., S.J. Rees and J.D. Spitler. 2007. Modeling Snow Melting on Heated Pavement Surfaces Part II: Experimental Validation. Journal of Applied Thermal Engineering. 27:1125-1131.<o:p></o:p> and then later applied it to look at what is needed for prediction of undisturbed ground temperatures; I view this as a precursor to predicting disturbed ground temperatures - the issues are basically the same, though we found that disturbed ground temperatures could also be influenced by shading from the building in some of our work related to foundation heat exchangers: <meta name="ProgId" content="Word.Document"> <meta name="Generator" content="Microsoft Word 14"> <meta name="Originator" content="Microsoft Word 14"> <link rel="File-List" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml">  <link rel="themeData" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"> <link rel="colorSchemeMapping" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml">  <style>  </style> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> Xu, H. and J.D. Spitler. 2011. Importance of moisture transport, snow cover and soil freezing to ground temperature predictions. Proceedings of the Nordic Symposium on Building Physics. May 2011. (I should also note that we found freezing and thawing in the ground to be important.)  Modeling of snow accumulation and melting is computationally demanding and would take some time to implement in any building simulation program.  It may well be that some clever individual has developed an approximate algorithm that is faster and "good enough".  If so, I would be quite interested to hear about it.  I am also very interested to hear if anyone else is involved in related research.  Ida - I am sorry not to have a more immediately helpful answer. Best wishes, Jeff Spitler <o:p></o:p> <meta name="ProgId" content="Word.Document"> <meta name="Generator" content="Microsoft Word 14"> <meta name="Originator" content="Microsoft Word 14"> <link rel="File-List" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml">  <link rel="themeData" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"> <link rel="colorSchemeMapping" href="file:///C:%5CUsers%5CSpitler%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml">  <style>  </style> On 5/24/2013 7:41 AM, Ida Auråen wrote: </div> <blockquote cite="mid:CAGkwxusXDv652+f541XUAHzeLzv4g9zCK5Q8D_KoNoVsxWd3vA@mail.gmail.com" type="cite"> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <div dir="ltr"> Hi,  I have a question regarding climate file and snow. If you are modeling a building in a cold climate where there is snow lying on the ground a significant time of the year, will ESP-r take this into account? Snow will insulate the ground and minimize the depth of frozen ground. The snow will also reflect solar radiation well and it will contribute to more passive solar heat through windows or to solar collectors/pv-panels. Is there snow on the ground for the simulations done in ESP-r in colder climates? Best Regards Ida Auråen </div> <fieldset class="mimeAttachmentHeader"></fieldset> <pre wrap="">_______________________________________________ esp-r mailing list <a class="moz-txt-link-abbreviated" href="mailto:esp-r@lists.strath.ac.uk">esp-r@lists.strath.ac.uk</a> <a class="moz-txt-link-freetext" href="http://lists.strath.ac.uk/mailman/listinfo/esp-r">http://lists.strath.ac.uk/mailman/listinfo/esp-r</a></pre> </blockquote> <pre class="moz-signature" cols="72">-- Jeffrey D. Spitler, PhD, PE Regents Professor and C.M. Leonard Professor School of Mechanical and Aerospace Engineering Oklahoma State University <a class="moz-txt-link-freetext" href="http://www.hvac.okstate.edu">http://www.hvac.okstate.edu</a> Ofc: 405-744-6578</pre> </body> </html>