The heat collector for a ground source heat pump, whether it is formed from a borehole array, horizontal ground loops or a water collector, is charged with a glycol/water mixture to form an antifreeze fluid. We then add a bacterial growth inhibiter to maximise the life of the glycol.
Some glycols, such as those based on ethylene glycol, are poisonous to people and most wildlife, and will pollute river and ground water in the event of a leak or accidental discharge. For this reason, isoenergy only use non-toxic, biodegradable glycol derived from propylene glycol, which is not a notifiable chemical and which is therefore of no immediate concern to the Environment Agency should there be a leak or accidental discharge. While the non-toxic, biodegradable glycol is more costly it is in keeping with Isoenergy’s ethos and our commitment to the environment, using products with low or zero environmental impact.