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I tend to be my own worst enemy by over thinking things. I am working with a very contemporary architect on 2 projects. These homes are both slab on grade with very open floor plans and limited interior walls. I am going to have to install my supply/return lines to remote manifold in the slab. I have done this in the past, but now I am wondering if I should insulate the S/R mains for a few reasons. First they will be running through other heating zones and rejecting heat along the way. Maybe creating warm spots. Next, if the S/R lines are loosing heating along the way to their zone the water temp will not be hot enough to satisfy the zone. One problem with this is I am working with a 4-5" slab with wire mesh and tubing in it and then these S/R lines will be installed over top of this assembly....not leaving very much space for concrete over top.
About 5 years I started insulating my S/R lines to my remote zone manifolds for performance and expansion sound. I like this system, but what about the slab.
Thanks for your input Jeffrey