Modular back side radiant heating panels with spring retention devices

A modular temperature controlling panel for location adjacent a rear side of a room surface and between spaced penetrable structural framing members for supporting said room surface, said panel comprising:

• an insulating core having a contact surface for location adjacent said room surface and a non-contact surface opposite said contact surface;
• a linear thermal source recessed within said core on said contact surface;
• a metallic sheet on said contact surface of said core for contacting said linear thermal source;
• a plurality of recessed cavities arranged in a grid pattern in the contact and non-contact surfaces of said core, said plurality of recessed cavities in said contact surface being separated from the plurality of recessed cavities in the non-contact surface by a separation layer;
• and
• a spring retention means on said non-contact surface of said core for securing said core between said spaced framing members and for urging said contact surface toward said room surface, said spring retention means being rotatable about a rotation axis perpendicular to said framing members between a loaded position for confining said spring retention means within said core and a secured position for biasing said spring retention means to penetrate said spaced framing members and urge said contact surface of said core toward said room surface.