'solar water heating' component outputs: multiple surfaces but only one tank!


Dear All,

I am using the solar water heater component to calculate the amount of auxiliary energy that I would need depending on the number of solar thermal collectors installed.

As I’m a new user, I can’t upload the file. But on the picture you can see the components I use and the panels on the second images show the results i’m talking about. I created 5 rows of solar thermal collectors and have a heating load for a house of 5 persons.

However, it seems that the component is treating each surface as a separate collector with its own tank. Moreover, the heating load per hour is considered as being per collector (and not for the whole house) - therefore at the end, the auxiliary energy calculated is x times to high (with x being the number of collector surfaces.
I don’t want to just average anything after the calculation, as the temperature of the Tank (depending on the heat from the collectors Qsolar) has a huge influence on the thermal gain in kWh.

Could the code be slighlty changed to sum up the solar gain of all collectors and input it in one tank only?
Or how can I merge all surfaces into one? (i have tried but without success)

I’m a bit confused on how to proceed.

Edit: Here’s the file: https://we.tl/t-DuDFjZ83cB

Thank’s for your help!


cc to @djordje please


You can use Wetransfer to share the file.


True, thanks. Here is the file: https://we.tl/t-DuDFjZ83cB

And @djordje: do you have an idea? Thank’s for your help!


Hi Alice,
I would use a single row of SWH collectors, do the calculation and then afterwards use the “PV SWH system size” component to determine the dimensions of my collectors, by assigning the number of rows input.
Attached is an example.
ladybug_swh_issue2.gh (88.4 KB)