Various problems calculating global insolation
1) All objects have been selected for the solar access analysis; the normal is pointing into the
right direction but: No color appears to indicate insolation, yet there are some very small
insolation values (about 1% of the neighbouring object). What can I do?
2) Why does the so called “exposed area” used in the solar exposure analysis differ so much
from the “surface area” shown in the selection information (719 m² exposed area as compared
to 514 m² surface area)? One time the exposed area was more than 100 times bigger than the
surface area. Do different values mean that the results in solar and thermal calculations are
wrong by the same percentage?
3) What exactly is the difference between using solar exposure analysis (“each object” or “sun
path”) or solar access analysis to calculate insolation? The results are very different in my
case and it seems to me as if diffuse radiation was almost neglected in “solar exposure, each
object”. I checked Ecotect results against two other programs (meteonorm, TRNSYS) using
the same weather data and only one object at a time (either horizontal or slightly sloped;
Azimuth 29°, slope 3° from horizontal). The following table lists the results.
solar exposure
solar access
meteonorm
TRNSYS
Object 13150, Azi=29°SE, slope=3° from horizontal
each object
131,5
sunpath
368,8
solar access
372,7
meteonorm
455,0
455,0
Horizontal
128,1
365,4
396,3
450,2
453,0
4) How can even the available radiation (971 kWh/m² in the solar access analysis) be smaller
then the radiation on the horizontal given in the wea weather file (attached weather file)? If I
open Frankfurt_weather.wea with the weather tool the annual global radiation is 1034
kWh/m² which represents the meteonorm value. Therefore the conversion into a wea was
correct.
5) objects are neglected in shading mask but OpenGL Visualisation shows that there are
objects. So what about calculations? Are they done as if there was a void?
Optimization
What possibilities are there to automatically optimize a building with regard to its insolation
values? Can you tell ecotect to optimize either the shape of a building for a given orientation
and location or the orientation of a building for a given location and shape, e.g. by
incremental rotations? The only possibility I see so far is to rotate the model manually and
compare results. The problem is that calculations use a lot of time and computing capacity so
it would be very useful to let the computer do 4 or 5 calculations at night and then compare
the results in the morning.
Thermal simulation
Is it possible to border a thermal zone by a void or do I need to take an open window? Does a
void need to be a child object of another object or can I span a void between one object and
another object? I would like to simulate a 30 cm gap between an amorphous tent structure and
the ground.