SOLVED:
The unexpected results were due to the significant impact of radiation on heat transfer within the space. In the Surface Heat Balance equation:
Surface Conduction to Exterior = Surface Received Radiation – Convection to Zone Air,
the result turned negative because the incoming radiation exceeded the convective heat transfer to the zone air.
Notes:
- This was confirmed by reducing the
solar absorptance and thermal
absorptance of the interior material
to near zero, which minimized the
effect of radiation.
- It was also observed that as the
windows of the space begin to receive
sunlight, surface conduction
progressively decreases. This
confirms that increased radiation
reduces conduction—potentially enough
to make it negative.
- To better understand the phenomenon,
the following outputs were compared:
Surface Inside Face Conduction,
Surface Outside Face Conduction, and
Surface Heat Storage.
- An image showing the comparison and
supporting the explanation is
attached.
