[Bldg-sim] Hourly Solar Hot Water modeling program

[Karen Walkerman]

Hi All,

Thanks for all the responses.  I will probably use WATSUN for this project,
but could use a hand with something:

for "Collector Test Data" the program requires that I enter in some test
parameters for the solar panel:

A (no units)
B (1/C)
C (W/m2/C)
D (W/m2/C2)
E (W/m2)

This data is used in the following formula:

Q = Area ((A + B dT) Akt H - (C + D dT) dT - E)

where:

Akt is the incidence angle modifier
H is the incoming solar radiation
dT is the temperature difference between the collector inlet and ambient air

The help file indicates that I should be able to get these numbers from the
manufacturer or from a testing agency, however, the data I have found
includes variables A, C and D, but not B and E according to test
EN-12975-1,2:2004.  Unfortunately the Help file gives no indication of what
test these numbers should come from or any other information.

Can anyone give me a hand here?

Thanks,

--
Karen

On Wed, Jul 29, 2009 at 11:26 AM, B. Fountain <bfountain at greensim.com>wrote:

> Karen,
>
> Transys is ideal for that type of analysis.  Another (cheaper) option to
> consider would be WATSUN from Natural Resources Canada.  It comes with
> .TMY for Canadian sites -- I do not know about compatibility with US .TMY
> data.  Price is right though.
>
> WATSUN is available (for free) here:
>
>
> http://canmetenergy-canmetenergie.nrcan-rncan.gc.ca/eng/software_tools/watsun.html
>
> I have not played much with it but it does produce hourly results to a
> text file. Note that it only uses SI units.
>
> Cheers,
> Brian
>
> > <Is anyone aware of a program that can model hourly outputs for a solar
> > hot water system?  I would prefer something that can accept a TMY2 or
> TMY3
> > weather file and just gives me the hourly heat output based on SHW panel,
> > inlet and outlet temperatures, angle and azumith.  I'll handle the load
> > side, including thermal storage, etc.>
> >
> > In my opinion, TRNSYS is probably the best program to handle your stated
> > solar domestic hot water simulation needs - at timesteps of an hour all
> > the way down below a second if you need that type of resolution.  But it
> > can also do the entire balance of system (thermal storage, controls,
> > interaction with the building, etc.). However, it's a bit on the pricey
> > side if you're only going to be using it for one project.
> >
> > Give us a call if you'd like to discuss your project.  We do a lot of
> > solar thermal projects and could help answer some of your modeling
> > questions.  Good luck with your project.
> >
> > Jeff
> >
> >
> > Jeff Thornton
> > President - TESS, LLC
> >
> > 22 North Carroll Street - Suite 370
> > Madison WI 53703 USA
> >
> > Phone: 608-274-2577
> > Fax: 608-278-1475
> > E-mail: thornton at tess-inc.com
> > Web: www.tess-inc.com
> >
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>
>
>
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