Move absorptance fields to Construction to better model roofs/radiant barriers/etc. #11393
Description
General Summary
I propose removing the three Absorptance fields from Material objects and adding them to Construction objects (separate values for interior and exterior), so that we can better model, e.g., residential roofs, radiant barriers, and some wall types.
Detailed Description
Currently Thermal/Solar/Visible Absorptance fields live on the Material, and the innermost/outermost material layers define the interior and exterior absorptances of a surface. The logic is based on the idea that a material has the same absorptances on both sides.
However, there are practical issues to this, particularly as they relate to CTF calculations. As noted here:
"There are potential issues with having a resistance-only layer at either the inner or outer most layers of a construction. A little or no mass layer there could receive intense thermal radiation from internal sources or the sun causing the temperature at the inner or outer surface to achieve very high levels. This is undesirable from a simulation standpoint as there are limits to temperature levels in EnergyPlus that could be exceeded causing the simulation to terminate ..."
Suppose you are trying to model a residential roof with thin asphalt shingles, 1/2" plywood, and that's it. CTF calculations often force us to combine the two materials together into a single-layer construction to avoid errors, but now you only have a single absorptance that can be used for both the interior and exterior. It's even more problematic if you wanted to model a radiant barrier (thin aluminum foil) on the interior.
Another example could be a wall that is only made up of one material (concrete?) but painted on the inside. Once again, there is no way to specify different interior/exterior absorptances, unless you were to create a very thin "paint" material layer, which can result in CTF errors.
To solve this, I think the three absorptance fields should be removed from the Material and added to the Construction with separate interior/exterior values.
This would probably also help with #9842.
Possible Implementation
No response