pallsopp42 wrote:EcoDesigner and EcoDesigner Star also seem to be over-estimating energy consumption. For a project in Phoenix, Arizona, we have R-35 wall and roof constructions with low solar absorptance external cladding materials, high efficiency windows and so on. Yet EcoDesigner way over estimates energy consumption per unit area per annum when compared to an ACTUAL building with R-Values are far less than in our building model. This "test building" has had its energy consumption monitored (for two occupants) for the past 5 years.
In my opinion, this happens because EcoDesigner has a fundamental deficiency that I brought to the attention of GRAPHISOFT in June of 2013, but nothing was done to correct it.
More over, this deficiency was carried on to EcoDesigner STAR
rendering this $2500-dollar add-on totally useless in energy calculations for buildings relying on solar gain or shading for sustainable strategies (aren't all sustainable buildings rely on that?).
In short, using any windows in your project, short of orienting then north, away from sun
, will show a constant solar gain throughout the year for those windows without taking into account widely marketed "model based shading".
Anybody can see that happening by creating a simple project with a window facing south and then placing a solid wall right in front of that window to block the sun completely. If one then looks at this window's solar analysis, one will find a properly shaded window receiving no sun throughout a year, but the energy report
will put a full solar gain load though that window anyway showing a tremendously high need for additional cooling.
I have no idea who does quality assurance in GRAPHISOFT, but assuming that this was brought to their attention last summer, releasing EcoDesigner STAR as a "Standard Compliant-NOT Simulation Engine"
for $2500 a pop is odd.
I am also curious, how can thousands of architects working on sustainable buildings worldwide not to be concerned about this glaring error and not start to voice their concern with spending thousands of dollars on licenses for software products that do not deliver what they are marketed to do?
I have a feeling that a rather cryptic manual that accompanies all EcoDesigner products has to do with people having difficulty understanding how the package works, let alone trying to find bugs and omissions, but yet, we are talking about a sun-related calculation being wrong and we don't get many sustainable design-related items as prominent as the Sun.
This issue was instantly apparent as soon as AC17 came out in 2013 being marketed as to having "model based shading" for standard EcoDesigner, then nothing changed in EcoDesigner BETA, and finally commercial version of EcoDesigner STAR has the same issue.
To sum up, this was brought to the attention of GRAPHISOFT as early as last summer (see this thread: Solar Analysis is not accounted in Energy Simulation (AC17)
Am I missing something?