The direct system is used in frost-free locations, where the ambient temperature never falls below 5°C and where the water quality is good (less than 600ppm Total Dissolved Solids/Minerals). The system is used with one or two Solar Collector Panels dependant on the capacity of the Solar tank.

The direct system, is where the water to be used in the household (hot water) circulates through the solar collector panels, transferring solar energy into the storage tank of the solar water heater.

The direct system can be installed as a Split System (pumped or thermosyphoned circulation methods), where the solar water heater is installed inside the roof or away from the solar collector panels or installed as a Close Coupled System (thermosyphon circulation), where the solar water heater is installed outside on the roof and above or higher than the solar collector panels (see section Circulation Methods).