Did you take into account the incidence angle modifiers when you calculated the efficiency?
As for the second issue, did you account for any pipe losses or pump energy gains to the fluid? Did you look to see if the differences you're calculating are within your simulation tolerances?
Jeff - TESS
Sent from my iPhone
> On Jun 20, 2017, at 8:11 PM, Rm Chemilo via TRNSYS-users <
trnsys-users@lists.onebuilding.org> wrote:
>
>
> In this attachment file, I tried to calculate hourly thermal efficiency of solar collector by using this two equation
> and
> . But after comparing the result, why the hourly efficiency different?
>
> And also please check "Comparison Energy balance" sheet. I don't understand why q gain from solar collector has different value with qin storage. even though in the example there is no heat exchanger between solar collector and storage.
>
>
> Thank you.
>
>
> <TRNSYS EXAMPLE SDHW.xlsx>