What is the output variable for heat transmitted through a wall, to compare a wall with and without PCM?
Hello everyone,
I am modeling a building in EnergyPlus and comparing two wall constructions: a reference wall without PCM and the same wall with a PCM layer (using MaterialProperty:PhaseChange with the CondFD solution algorithm). My goal is to evaluate the insulation effect of the PCM by comparing the heat transmitted through the wall in both cases.
I could not determine which output variable is the right one for this purpose, and I would like to make sure I am reading the correct quantity.
My questions are:
Which output variable represents the heat actually transmitted through the wall into the zone, so that I can compare the two constructions?
Any advice on best practice, or pitfalls when interpreting these results with PCM, would be greatly appreciated.
Thank you in advance!
For possible pitfalls, a wall using PCMs has a lot of "memory". A PCM with a phase change temperature of 28-31o used to try and reduce maximum interior temperatures could suffer from not recharging in a sequence of very hot nights. And as the wall will present different conductivities, some equations that use averages will simply not be usable, so your timestep and output resultsshould take that into account.