Down comers are also forms of internal hydrant for the firemen to use and are always charged with water tank located at the top of a building but without any pumps. Down comers are only permitted for private residential buildings with open balcony approach where the topmost floor is not higher than 60 meters above the fire appliance access level and should be adopted for low cost flats only.

Down comers system comprises a high level water storage tank discharging into 150mm diameter riser pipe with landing valves at each floor and to which canvas hose with nozzles can be connected to direct the water jet at the fire. No pumps are provided and therefore the system pressure is limited to the static pressure only.