This type of solar water heater provides mains pressure pre-heating via a highly effective copper coil heat exchanger located within the solar collector tank. Rather than using the water in the tank directly, as the non-pressured does, this type uses a 45~60m copper coil.
Heat exchanger inside the tank which provides more than 1.5m2 of heat transfer area. When water flows through the coil, it absorbs heat from the water inside the solar collector tank. The solar collector tank is therefore a thermal store.