Design info

Drainage Capacities

Type of rain chainMaxDrainage: Liter/sec. *1Recommended Max Drainage: Liter/sec. *2
Tama0.20.1
Toh0.20.1
Ta-ke0.20.1
Migumo0.250.1
Migumo L0.650.4
Ajiro0.20.1
Hamon0.20.1

*1 This figure indicates the maximum amount of water (liter/sec.) that a particular rain chain is able to drain. It will disperse some but the water will be drained.   
*2 This figure indicates the maximum amount of water that a particular rain chain is able to drain water in a collective manner without dispersing.

Miscellaneous

If the roof area is exceptionally large and the drain capacity of the rain chains are not sufficient, you may consider using rain chains and conventional sprouts together, or consider other mechanisms that will prevent overflow of rain water in the roof gutter. One method would be to build a mechanism similar to a gargoyle at the end of the roof gutter if you have a spot where you could drop water as an emergency measure.