Closed Loop Systems
Closed Loops utilize high-density polyethylene pipe buried horizontally or vertically. The nonbiodegradable buried pipe is filled with an antifreeze solution, allowing lower solution temperatures to reach the heat pump. Temperatures can be well below freezing generating the need for an antifreeze solution rather than pure water to prevent freezing in the heat pump heat exchangers or piping. As the plastic piping creates another heat transfer barrier, earth water solution temperatures must be lower in the winter and higher in the summer.