What is an open loop?
AOne pipe is used to take water directly from a lake or river, or an underground well or aquifer. The water is circulated through the heat pump to extract the heat, and a second pipe is used to return the water to the same source. Standards dictate that the amount of water extracted cannot impact negatively on the ecosystem, and consideration must be given to discharge areas to avoid impacts (eg: if slightly warmer water is discharged into a lake during summer, the discharge should not be located near sensitive aquatic life).
