Flow Rate (Q)
- The rate of flow of rainwater to be drained away from a roof under steady state conditions shall be calculated from equation 1:
where;
is the rate of flow of water, in litres per second (l/s);
is the rainfall intensity, in litres per second per squre metre ;
is the effective roof area, in square metres ;
is a runoff coefficient (taken as 1.0 unless national and local regulations and practice state otherwise), dimensionless.
Reference
- BS EN 12056-3:2000