The foundation has begun!

In addition to the work on the geothermal heat pump we have been getting started  on the foundation of our net-zero project in Durham.  The foundation for this project has included a combination of 10" poured concrete walls (where significant retainage is needed)  and standard concrete block where the grade is less severe. The penetrations in the poured concrete wall show the large opening where our mechanicals,  (electric, plumbing, radiant piping, and pvc hvac supply ducts) will all be installed under the slab.

Geothermal Heat Pump installation

An exciting and energy/cost saving feature of our future "net-zero" project in Durham is the geothermal heat pump.
Geothermal heat pumps are able to heat, cool, and, if so equipped, supply homes and buildings with hot water. A geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger—a system of pipes buried in shallow ground. In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger. The heat removed from the indoor air during the summer can also be used to provide a free source of hot water. Source: U.S Department of Energy
A typical closed loop system is installed horizontally or vertically, as seen in the images below. Source: U.S. Department of Energy With this home we were able to take advantage of a natural depression in the lot to install a horizontal loop geothermal "slinky."   This gets the piping down about eight feet without the extensive costs associated with trenching for vertical or horizontal loops.