Using Google Sketch-up as a design tool.
user-757117
| Posted in General Questions on
Just wondering if anyone has ever built a window overhang that was designed using the shadow simulation feature in Google Sketch-up? If so, how did it turn out? How accurate was the modeling?
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Lucas,
I haven't used Google Sketch-up for that purpose, but I have found these free online design tools to be extremely useful:
http://susdesign.com/overhang_annual/index.php
http://susdesign.com/overhang/index.php
Hi Lucas
I have only dabbled with that feature and cannot attest as to its accuracy. Fun to play with though. Gary Reysa over at Builditsolar has reported on how it worked for him.
http://www.builditsolar.com/References/SketchUp/SketchUpEx.htm
Thanks guys.
Haven't tried sketch-up for modeling designing overhangs but have found this site extremely useful: http://www.susdesign.com/overhang/ I'd venture to say that this tool is very accurate, as overhang design is its only function. You could use model the same window in both programs and see how they match up...
I use Sketch-up and love it. I ran shade ideas thru it actually for the redesign of my own front entry though the project has not been completed. Gary Katz has a good tutorial that I just used to help me design a custom pantry. Accuracy is up to the user, the software is accurate. Use the "save as" feature and save extra versions of your project as you draw. That way you can always start over just a bit back if for any reason you find the need to and also explore multiple options. Sometimes I just find that a prior state of a design is better than where I may be at in a present point. Good luck.
Lucas,
I would assume solar paths have been nailed down mathematically for some time now and that any software that places the sun per the date and time uses the same projection formulas.
Yah, but wait 'till we hit the 2012 pole shift and the earth reverses its spin - that's really gonna throw off the sun charts.
All that's necessary to design solar overhangs are two simple mathematical formulas that can easily be incorporated into a spreadsheet to allow easy alteration of variables.
The more we rely on 3D simulations and rendering programs the more we lose our innate ability to visualize spatial relationships, which has always been considered a core element of human intelligence. And the more we rely on programmers to help us design, the less capable we become to apply basic mathematics to our design problems.
We're going to have an entire generation of designers who cannot function when the power grid crashes.
I had forgotten I had asked this question.
You see, using Sketchup also destroys your memory ;-)
Good point.
That would be like someone with multiple terminal cancers being hit by a bus while crossing the street. ;-)
I've always had a problem with the idea that we can use either a simple spreadsheet or more complex modeling software to calculate a precise and ideal overhang for a given situation, as the times that we wish for maximum and minimum insolation generally occur a couple of months AFTER the solstices. The perfect sunlight admittance for late February is going to be excessive (at least in our neck of the woods) in October, and an overhang calculated for June 21st is going to be inadequate in late August, our hottest month. Adjustments for time of day and for external factors (adjacent buildings, patios, deciduous and evergreen trees) and internal factors (daylighting requirements, the nature and orientation of interior walls and and other surfaces) complicate the situation even more. Consequently I've tended to treat shading design as more of an art than a science, and I have found visual computer modeling of the flow of sunlight through an interior and across an exterior over time to be much more useful in support of that art than any spreadsheet.
By the way I use Vectorworks rather than Sketchup for this purpose - it has a much steeper learning curve and is not for casual users but has the great advantage of complete two-way integral linkage between production drawings and the 3D model.
James,
Of course overhang design, like the entirety of passive solar design, and like design in general is an art not a science, though science helps inform good design.
And no one suggested that there's "a precise and ideal overhang for a given situation". There are, however, good rules of thumb for those who want shortcuts that work reasonably well, but the goal is always optimum not perfect solar shading and insolation.
My simple spreadsheet gives me the illumined area of the floor at any given sun angle (initial floor contact and termination of contact, which is often up the center bearing wall). It's easy to download a sunchart for your zipcode (or lat long) from http://solardat.uoregon.edu/SunChartProgram.html and enter any sun angle for any time of year or time of day.
The great advantage of a spreadsheet is that it allows immediate feedback from changing any single parameter so it's very easy to play with options until the optimum solution is found. Frankly it amazes me that so few designers and builders use spreadsheets, which I find to be the single most valuable tool for the design process as well as for thermal engineering, solar engineering, structural engineering and even laying out rafters or stairs.
Rivertsong,
See, you are a Passivhaus advocate ; )
Rivertsong!
Chesnut, you are subtle.
PassiveHaus advocate? Not hardly.
I'm not suggesting we use someone else's super-complicated spreadsheet. That's no different than relying on any incomprehensible proprietary software.
I'm suggesting that we each design our own spreadsheets to meet our individual needs. Spreadsheets enable anyone to be their own programmer. Then you know exactly how the outcomes are determined by the inputs, and you can include the variables that you feel are important. But it requires that you really understand the dynamics and some basic mathematics, which few are willing to take the time to do.
Everyone wants to be little more than consumers of someone else's work, rather than really understanding the foundations of their trade.
I thought the polar shift was going to kill the gulf stream, not change the earth's rotation....
"Everyone wants to be little more than consumers of someone else's work, rather than really understanding the foundations of their trade."
Really? Dull crowd you must hang with.
Yah, this one.
It's all those polar bears running like crazy to get away from the melting sea ice that will reverse the spin of the earth on its axis - that's the Polar Bear Shift.
Seriously, though, there is some fear the the viscosity of the oil plumes from the BP blowout can slow or stop the Gulf Stream and put England into an ice age.
Pole Shift & Pole Reversal in 2012
by Patrick Geryl
In 2012 the next polar reversal will take place on earth.
This means that the North Pole will be changed into the South Pole. Scientifically this can only be explained by the fact that the earth will start rotating in the opposite direction, together with a huge disaster of unknown proportions.
In my books I reveal the immense cataclysm that is going to torment the earth in the near future. It is presently assumed by most people and the general scientific world at large, that the rotation of the Earth is stable, however, as expounded in my previous works on this subject, this is not the case. The gruesome reports of the previous catastrophes should, hopefully, be clear to all.
The historical exploration of cosmology in previous books is founded on the translation of hieroglyphs, cracking of codes, unveiling of the magnetic reversal of the sun, study of old maps, decoding of astronomical clues, geological research, and the discovery of the most exciting archaeological find in modern times.
Considering these I came to the following conclusions:
With clock-like regularity, sudden reversals and pole shifts are natural to the Earth.
The result is worldwide destruction, and is supported by paleo-magnetic evidence and early manuscripts.
The reversal of the poles is attributed to the harmonic cycle of the magnetic fields of the sun.
Polar reversals can be calculated precisely on the basis of the sunspot cycle theory or the magnetic field theory, which the Maya and the Old Egyptians were privy to.
Just trying to attach a sketchup file ...winter solstice
And summer solstice
What about winter solstice with a full lunar eclipse?
And why are your pictures labeled June 13 and Nov 13?
Here you go Robert
Garth... need to give you extra ++++++ for the first exact answer to a question ever given at GBA.
Bravo my man. Keep up the great work and posting. I have your back... with the + button. LOL
Garth, is that your house? If so, how do those shadows compare to the ones you see outside?
Lucas
This is just a model of a plan we have been working on. The shadows should be very accurate though. With Sketchup, you can input your exact location via Google Earth. Sketchup is a lot of fun to play with. Have you tried it yet?
Yes, I have have been puttering around with it for a while now, though I had put it on the shelf for the summer. I just downloaded V. 8 last week and am pleased with how much smoother everthing works.
I was never really sure how accurate the shadow modeling is but I have stopped worrying about it now. I was just curious though if you had an observation to provide.
If I can find the time to finish it, I have a sketchup drawing I've been meaning to post for discussion.
So Garth, have you decided on a foundation type? Those insulated raft foundations described in Martin's recent blog entry could work well with your extreme soils.
John and Lucas
I just set up a deck of cards (about 4" high) on my desk and measured the shadow...then modeled it in Sketchup for same time and location. Seemed to be bang on.
I attempted sketchup on a couple of study models.
made progress at first ... but then learning got to be time intensive.
attached is an unfinished project
Sketchup Location set for Dallas,TX
If you Have Sketchup .... here is the SKP file
http://dl.dropbox.com/u/16030874/gable3.skp
Lucas,
I am guessing that Sketchup is rather accurate.
If you are really curious
why don't you build a crude mock-up (perhaps a yard stick)
model it in Sketchup and then measure the shadow on your real world mock-up