This document provides an introduction to geothermal comfort systems. It defines geothermal energy as relating to the internal heat of the earth, noting that the earth acts as a giant solar collector. It distinguishes between high-temperature geothermal from deep underground and low-temperature geothermal, which utilizes shallow earth temperatures via a heat pump. The basic system involves circulating water through underground pipes to transfer heat to and from the ground. During heating the earth serves as a heat source, and during cooling it serves as a heat sink.

1. Introduction to Geothermal Comfort Systems

13. Heating Mode Operation

14. Cooling Mode Operation

15. The Basic Refrigeration Cycle Compressor Condenser Evaporator TXV High Pressure Vapor State High Pressure Liquid State Low Pressure Liquid State Low Pressure Vapor State

19. Typical Earth Loop Features Circuit Piping (usually ¾” or 1” IPS) Multiple Circuits (trenches or bores) Header Pit Reverse-Return Header Supply & Return Piping (usually 1-1/4” or 1-1/2” IPS) Foundation Penetration Equipment & Flow Center

21. Horizontal 4 & 6 Pipe Loops

22. Horizontal Slinky Loops

23. Horizontal Bore Loops

24. Horizontal Pond/Lake Loops

25. Horizontal Pond/Lake Loops Slim Jim Lake Plate Heat Exchanger

26. Vertical Loops

27. Typical Installation – Closed Loop

29. Typical Installation – Open Loop