3,265 sf home under construction with 3-ton GeoComfort closed loop GSHP. Horizontal loop field is 3200' of 3/4'' HDPE in four, flat slinky runs buried at 7 feet in poor soil. Trench lengths are 87 feet long by 42'' wide, and wing outward at 180° from two header pits near front and back of house. All slinkies encased in one foot of compacted, fine silt that holds water very well. At the 2-foot level above each trench, 4'' diameter, laser-leveled leach pipes in drain rock (covered by industrial fabric and buried) deliver downspout and surface drainage to ''water'' the trenches, keeping the loop pipes surrounded by wetter, more conductive silt.
System will also contain three ducted zones w/thermostats, a de-superheater loop to a two-tank DHW system, timed circulation to hot water use points, heat recovery ventilator, electronic air filter, and humidifier.
All electric home in a 13¢/kwh environment at 5852 heating degree days. ASHRAE winter design temperature for this Sierra Nevada 3500' mountain location is +10°F. Projected total cost in January is $170 or less for heat, hot water, lights, refrigeration, cooking, and laundry. That's $5.20/100sf/month.