I have a pond nearby. Can I put a loop in it? Yes, if it’s deep enough and large enough. A minimum of six feet in depth at its lowest level during the year is needed for a pond to be considered. The amount of surface area required depends on the heating and cooling loads of the structure. You should opt against using water from a spring, pond, lake or river as a source for an open loop system unless it’s proven to be free of excessive particles and organic matter. They can clog a heat pump system and make it inoperable in a short time. Back To FAQs