Heat balance on wall inside surface

edit

Hello.

I studid heat balance in energyplus. I want to know heat balance between wall inside surface and zone. (The Zone, no HVAC)

In Engineering reference, eqation is

qlwx+qsw+qlws+qki+qsol+qconv =0

but, when I add all, I can't get a Zero.

Surface inside face net surfaced thermal radiation heat gain rate per area + Surface inside face solar radiation heat gain rate per area + Surface inside face lights radiation heat gain rate per area + Surface inside face internal gains radiation heat gain rate per area + Surface inside face system radiation heat gain rate per area + Surface inside face convection heat gain rate per area + surface average face conduction heat gain rate per area

Why..?