Best way to report solar gain in load reports?

Hi everyone, I’m in need of some opinions. I have recently discovered that the way solar gain is reported on my load calculations doesn’t work the way I thought. I always assumed solar gain meant the amount of heat entering the air in my space due to solar radiation coming through the window, i.e. heat the must be removed by the HVAC system. However, it turns out that according to the assumptions in heat balance method, air is 100% transparent to solar radiation. So that solar gain actually gets absorbed by internal surfaces, such as the floor and partitions. So when you have a lot of sun hitting an internal partition, it will report that it has a negative gain, as if I’m losing heat through the wall. But in reality, the wall takes in some amount of solar radiation which it counts as a negative gain and heats up the wall, then some, but not all, of that heat comes back out of the wall through convection which counts as a positive gain. So what ultimately gets reported for the internal wall gain is the net value. So even if the wall is adding heat to the air, the wall gain can be a negative value.

I found this confusing at first, but the math checks out now that I get the idea. The question I have for you all is do you think that’s the best way to report this? Or would it be better to report gains from *the perspective of the air*? In that case I think it still may be confusing, because then the solar gain item would simply go away completely. In either case the totaled gains add up the same.

So, option 1: report solar gain, understanding that this gain never enters the air itself, it can only go first into a surface to then be partially released back out through convection,

Or option 2: report only the heat going into or out of the air volume, meaning that the solar gain would not appear at all.

View Poll