An installer is asked to create a three-zone radiant floor heating system using a 5-ton (60,000 Btu/h) single-speed geothermal water-to-water heat pump as the primary heat source, and a mod/con boiler as the auxiliary heat source. The heat pump is supplied by 4 earth loops made of 1” HDPE tubing, with each loop being 500 feet long.

Each of the three zones will have a six-circuit manifold station with nearly identical circuit lengths. All the floor heating circuits are underfloor tubing with aluminum plates stapled tightly to the underside of the subfloor, and well insulated.