scope:

INTRODUCTION

Geothermal or geoexchange heating and cooling systems, also referred to as "ground source", "ground-coupled" or "earth energy" heat pump systems, are "…self-contained, electrically-powered systems that take advantage of the Earth's relatively constant, moderate ground temperature to provide heating, cooling, and domestic hot water more efficiently and less expensively than would be possible through other conventional heating and cooling technologies" according to IGSHPA, the International Ground Source Heat Pump Association.

The three primary categories of geothermal or geoexchange heating and cooling systems are commonly referred to as closed-loop, open-loop and direct-exchange:

• Closed-loop systems utilize plastic piping systems for the ground-coupled heat exchanger piping system, and are the primary focus of this technical note.

• Open-loop systems utilize ground water or surface water for the purpose of extracting or rejecting heat, as the water is circulated through a mechanical heat pump. While open-loop systems utilize the types of plastic pipes included in this Technical Note, these systems are not the focus of this document.

• Direct-exchange systems utilize copper tubing embedded in the ground with refrigerant circulating directly within this buried copper tubing. These systems will not be addressed in this Technical Note.