The influence of the solar radiation volume
The annual sunshine fluctuates depending on the location.

The influence of the angle of pitch and south-facing position
The maximum yield is registered with a purely south-facing position and 45° pitch. In reality, however, the penalties are hardly significant with orientation between southeast and south-west or pitches between 30 and 50°. Greater differences (east or west-facing roof) can be compensated for by making the collector area bigger.

Rules of thumb for dimensioning
In the case of average consumption and good orientation, around 1 to 1,5 m2 of Roth flat collectors are required per person for 60 % coverage. For the solar tank capacity, 1,5 to 2 times the daily hot water requirement is applied.