Ground Source | SimplyHeating

Ground source heat pumps have been used for a very long time, they take their energy source from the ground, as the name suggests, howthis shouldn't be confused with geothermal energy we uses the heat generated within the structure of the earth, but is generally driven by solar energy the heats the ground, this is even true when looking at boreholes, not just horizontal arrays

Horizontal array,

this system is comprised of pipework laid horizontally in trenches at a depth of about 1 m spaced evenly to harvest thermal energy from the ground, the fluid that circulates bring these loops is a glycol based antifreeze, that is treated with an inhibitor to reduce corrosion, and with a biocide to prevent bacterial growth within the pipework. the glycol is diluted to protect the system against temperatures of -20 C (this is a requirement set out by MCS)

this pipe can be laid as a loop put and back to a manifold, with mutlitple loops connected to a manifold, (very similar in its configuration to underfloor heating, just bigger pipes) bigger heat pump systems, requiring more energy could' have multiple manifolds, covering thousands of square meters.

A slinky is a variation on this theme, but rather than straight pipe runs the pipe is laid a coils in the trench,

Vertical arrays,

more commonly referred to as bore holes, this arrangement uses holes drilled certainly into the ground. the depth and number of boreholes is determined by the amount of thermal energy that needs to be harvested, and the geology of the ground being drilled.

generally depths can vary from 20 - 30 m to 200+ m but this really does require very specialist equipment, and k knowledge.

pipe is then inserted in to the borehole, that is then back filled with a thermal grout to aid heat transfer, the same kind of heat transfer fluid is then circulated thought the pipe and then back to the heat pump,

generally the actual heat pump units are identical for the variations of ground collector array.

certainly the vast majority of the internal system components for DHW and SH are not influenced by the source of heat in this case

There are some challenges with ground source,

1. Space is required, of rat e horizontal top arrays about 2.5 to 3 x the internal floor area of the building will be required as a rough rule of thumb, for bore holes, this can be greatly reduced, as along as there is access for the drilling rig, and its accosicated components

This also attracts some considerable costs, however, is you have ground workers on site, then the digging for a horizontal array becomes much more