NAME
Sim::OPT::Modish
SYNOPSIS
re.pl (optional) use Sim::OPT::Modish; modish( "PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg", zone_number, surface_1_number, surface_2_number, ..., surface_n_number );
Example: modish( "/home/x/model/cfg/model.cfg", 1, 7, 9 ); (Which means: calculate for zone 1, surfaces 7 and 9.)
DESCRIPTION
modish is a program for altering the shading values calculated by the ESP-r building simulation platform to take into account reflections from obstructions. More precisely, modish brings into account the reflective effect of solar obstructions on solar gains on building models on the basis of irradiance ratios. Those ratios are obtained combining the direct radiation on a surface and the total radiation calculated by the means of a raytracer (Radiance) on the same surface.
The effect of solar reflections is taken into account at each hour on the basis of the ratios between the irradiances measured at the models' surfaces in a model anologue of the original one, and a twin fictiotious model derived from that. The irradiances are calculated through Radiance and derive from a model in which the solar obstructions have their true reflectivity and a model in which the solar obstructions are black.
The value given by 1 minus those irradiance ratios gives the diffuse shading factors that are put in the ISH file in place of the original values.
The original ISH's ".shda" files are not substituted. Two new files are added in the "zone" folder of the ESP-r model: a ".mod.shda" file which is usable by ESP-r and features the new shading factors; a ".report.shda" file which lists the original shading factors and, at the bottom, the irradiance ratios from which the new shading factors in the ".mod.shda" file have been derived. When the radiation on a surface is increased, instead of decreased, as an effect of reflections on obstructions, the shading factor can be negative, and the irradiance ratio is greater than 1.
To this procedure another procedure can be chained to take additionally into account in the shading effect of the obstrucontions with respect to the radiation reflected from the ground.
Finally, modish is capable of calculating the shading factors from scratch.
At the moment, the documentation describing how these operations are obtained and other information is inserted at the beginning of the source code.
The settings for managing modish are specified in the "modish_defaults.pl" configuration file in the example folder and also written as a comment at the beginning of the source code. This file must be placed in the same directory from which modish is called.
To launch modish, if it is installed as a Perl module:
use Sim::OPT::Modish;
modish( "PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg", zone_number, surface_1_number, surface_2_number, ..., surface_n_number );
Example: modish( "/home/x/model/cfg/model.cfg", 1, 7, 9 );
If instead the file Modish.pm is used as a script, it has to be launched from the command like with:
perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg zone_number surface_1_number surface_2_number surface_n_number
For example:
perl ./Modish.pm/home/x/model/cfg/model.cfg 1 7 9 (which means: calculate for zone 1, surfaces 7 and 9.)
(It should be noted that in embedded mode Modish.pm instead is called in a different manner by ESP-r: perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg -day day_number month_number -zone zone_number, and tests all the transparent surfaces of that zone.
The path of the ESP-r model configuration file has to be specified in full, like in the example above.
To be sure that the code works as a script, the header "package" etc. should be transformed into a comment.
In this case, if the surface numbers is omitted...:
perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg zone_number surface_1_number surface_2_number surface_n_number
... all the transparent surfaces of that zone will be processed.
By specifying the zone explicitly, it is possible to process also opaque surfaces, if needed.
In the case that Modish is used as a command-line program, it is also possible to call specific zones and surfaces explicitly, by linking the sequences "zone_number surface_1_number ... surface_n_number with "and":
perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg 1 7 9 and 2 16 and 5 7 9
It is also possible to omit the surfaces from the lists. In that cases, all surfaces of those zones get processed:
perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg 1 and 2 and 5
If no zones and no surfaces as specified, all transparent surfaces in all zones are processed. This might be slow, however:
perl ./Modish.pm PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg
Another manner for specifying the zones and surfaces to be processed are writing them at the top of the file "modish_request.pl" in the cfg folder of the ESP-r model. That line will override the specifications from the command line.
The functionality of Modish can also be accessed from inside ESP-r. About how to do that, see the ESP-r menus ("context").
When Modish is launched from within ESP-r, it can also be used in embedded mode - that is, the calculations regarding the reflections from obstructions can be less than hourly.
In calculating the irradiance ratios, the program defaults to: 5 direction vectors; diffuse reflections: 2 ; direct reflections: 7; surface grid: 2 x 2; distance from the surface for calculating the irradiances: 0.01 (metres).
For the program to work correctly, the ESP-r model materials, construction and optics databases must be local to the model.
Included in the example folder there is there is an example of configuration file "modish_defaults.pl". Explanations are written in the comments at the beginning of the source code.
EXPORT
"modish".
AUTHOR
Gian Luca Brunetti, <gianluca.brunetti@polimi.it>. The subroutine "createconstrdbfile" has been modified by ESRU (2018), University of Strathclyde, Glasgow to adapt it to the new ESP-r construction database format.
COPYRIGHT AND LICENSE
Copyright (C) 2008-2021 by Gian Luca Brunetti and Politecnico di Milano. This is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 3.