IRSTUFF is right. The heater position below the insulation layer only takes advantage of the insulation. If the heater was closer to the glycol, then you could use the other insulation layers to help reduce the heat load.
Incropera and DeWitt (Fundamentals of Heat and Mass Transfer) list the following values for cement mortar.
Thermal conductivity = .72 W/m K
Density = 1860 kg/m^3
Specific Heat = 780 J/kg K
I assume that the references in this book could also point you to more information about other building...
I calculated 12 Watts per m^2. This problem looks like a 1D problem and you want to know what would be the required makeup heat to keep your glycol at 20 degrees C. My assumptions were:
1. The interface between the glycol and the steel is at 20 degrees C
2. The interface between the air and...
Books
Finite Element Analysis: Theory and Application with Ansys by Saeed Moaveni
Ansys Tutorial by Kent L. Lawrence
Web Tutorials
www.andrew.cmu.edu/course/24-ansys/problems.htm
www.mece.ualberta.ca/tutorials/ansys/IT/TransCond/TransCond.html