We chose a GeoExchange (geothermal) system to heat and cool our house for its energy efficiency and because it does not rely on burning fossil fuels. It is also extremely quiet while operating. Although a GeoExchange system is initially more expensive to install, (due to the borehole drilling) we hope to see a payback for the incremental cost over a conventional HVAC system within seven years.
Trey Austin, with Geo-Energy Services has designed a GeoExchange system for our house utilizing three vertical boreholes as both a heat source and a heat sink. A hydronic pump will carry glycol or a similar liquid through a closed looped pipe system in series through the boreholes to a ground heat exchange system in our basement which will transfer the heat to an ozone-safe R-410A refrigerant.
Depending on the indoor temperature requirements, a heat pump (compressor) will add or remove heat through a distribution subsystem (fan and ductwork) throughout the house.
For this project, Geo-Energy Services has specified a WaterFurnace Envision Series system with a 2-stage Copeland Scroll UltraTech (dual capacity) compressor. 4-zones will be independently controlled with an Intellizone thermostat for greater efficiency.
In addition, the excess heat produced by the compressor will preheat our domestic hot water regardless of which direction the pump is running.
Installation of the GeoExchange vertical boreholes and piping will take place prior to the site excavation for our foundation due to the size of the equipment required to drill, retain and grout the 350’ deep holes.
This plan shows the borehole locations along our east property line. They should be spaced at least 10’ to 15’ apart for adequate thermal mass. The closed loop connections and piping to the basement will be about 6’ below the surface of our yard.