What Is a Desuperheater?

A desuperheater is an auxiliary heat exchanger that captures surplus heat from a geothermal heat pump's hot refrigerant gas and transfers it to the domestic hot water tank. It makes use of heat the system is rejecting anyway, principally while the system is running in cooling mode.

Also called: desuperheater coil · hot water assist

Why it matters to you

Its contribution tracks how much the system runs, which on the Crystal Coast means it does most of its work through a long cooling season — the months when the heat pump is rejecting heat continuously and that heat would otherwise go to the ground.

What to do about it

A desuperheater supplements the water heater rather than replacing it; the tank still needs its own heat source for periods when the system is idle. Ask whether one is included and how it is plumbed to the existing tank.