[Bldg-sim] 100 simulations

[Aaron Powers]

Jason,

This is something I'm interested in as well.  I think all the preliminary
design factors that you mentioned are great things to look at.  On the
later parts of the design process, control parameters are also good things
to look at (CHW plant control optimization, air-side control optimization,
etc.).

One way to convey the information is through simple 2D plots.  Below is an
example of 200 DOE2 simulations while varying the window to wall ratio and
another plot of 81 simulations varying the window shading coefficient.

[image: Inline image 1][image: Inline image 2]



Unfortunately, this does not convey the interactive nature of optimization
over multiple variables.  Using multidimensional optimization algorithms
can be another useful tool, but they can be tricky.  As an example, below
is a case of looking for the optimal minimum condenser water flow in a
variable flow condenser system.  From looking at the first plot, the
function seems relatively smooth and it's obvious that there's an optimal
in the neighborhood of 0.6.  However, if you zoom in (second plot), you can
see that the data is not very smooth, and there are all kinds of jagged
local minima/maxima.  These will tend to throw off most optimization
algorithms, which is why I think it's helpful to consider looking at
automated mass simulations before taking on the problem of optimization.

[image: Inline image 5]

[image: Inline image 4]
Aaron

On Wed, Sep 9, 2015 at 4:33 PM, Jason Glazer <jglazer at gard.com> wrote:

> I am just finishing up a project that performed about 60 automated
> simulations (using Python with EnergyPlus and Eppy) for a series of
> buildings in a bunch of cities. The power of automating simulations to
> understand the energy savings of different measures is very impressive no
> matter what tools are being used.  It has made me wonder about when does
> automation make the most sense during the design process and what
> information can be provided to an architect or entire building design team
> to encourage low energy building design.  I am thinking one of the most
> influential times might be during the architectural programming and early
> conceptual design steps. At this point the number of separate pieces of
> information is probably low enough that it could be filled out on a web
> form:
>
>  - number of occupants
>
>  - amount of area needed for different types of spaces
>
>  - location of the lot lines
>
>  - building location
>
> Conceivably, with that information, all sorts of various building
> configurations could be created automatically by a clever script then
> simulated and the resulting answers summarized.
>
>  - How many floor building uses the least energy?
>
>  - What shape building uses the least energy?
>
>  - What is the impact of more roof insulation?
>
>  - What is the impact of more or less fenestration on loads and
> daylighting?
>
> I would not expect the design team to use any of the automatically created
> building models directly but it might influence the design process in a
> good way if it was easy to get and easy to understand. I understand people
> have been researching the optimization of these kinds of factors but I am
> not sure that is necessary. Maybe just several different series of
> simulations illustrating various building options and their impact onenergy
> might be enough to get the discussion going.
>
>  - So what questions do you think could be answered by such an automated
> system during early conceptual design?
>
>  - How would you best convey that information to the building design team?
>
>  - Are there other times that a suite of automated simulations would make
> sense?
>
> A lot of useful information could be generated with a hundred automated
> simulations!
>
> Jason
>
> --
> Jason Glazer, P.E., GARD Analytics, 90.1 ECB chair
> Admin for onebuilding.org building performance mailing lists
>
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-- 
Sent from my DynaTAC 8000x
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