Does solar gain affect on heating loads?


I was wondering why a change of eave lengh doesn’t really affect the annual heating loads. I think, extending eave decreases cooling loads and increases heating loads, however heating loads is little change as you can see the figure.

Why doesn’t solar gain affect on heating loads?

epw : Tokyo
Left side : eave 0m, heating load : 4128kwh
Right side : eave 1.5m, heating load : 4105kwh

heatingload_coolingload_ver2.3dm (1022.1 KB)

heating load_cooling (782.1 KB)

All the best

@Yuki, I suspect your horizontal shade is blocking the high summer sun, and not having an effect on the lower winter sun. Take a look at your sun path during the heating season to confirm this. If you modified the shading geometry to account for the sun path during your heating season (extend the horizontal shade, add vertical fins), you’ll likely see a change in the heating loads.


Thank you for your advice.
I checked sunpath, and horizontal shade doesn’t cut off sun, exactly what you said.

Then, I try to extent horizontal shade 7.5m to cut off sun, but there are little change in the heating load.

eave 7.5m, heating load : 4109kwh

thank you for reading

All the best