Earth Coupled Loop (gle) alone to a heat-exchanger/and a blower, etc, or “radiant” using an interior tubing in-floor, etc…?
– for clean Earth-Tube (geothermal piping) to pre-cool or pre-heat a space ??
Or even to a radiant layout just to keep a slab area above freezing (in a barn for an RV, etc.? (Schools have used this for several years WITHOUT heat-pumps in the fluid loop to a ground source.) -All is like a solar collector, but is an ECL Earth Collector Loop (24/7 all year, use) 100% Sustainable , less a circulator and internal distribution identical to solar distribution subtracting from the sustainability.

Are there any energy retrofit details/drawings? (-have heard of Japan’s bridges kept from freezing with ocean water-tubing circulation for GT “warming”.)