The OSO Dualstream is a unique concept that takes the performance of an unvented cylinder to another level. Traditional unvented cylinders are dependent upon the incoming mains pressure and flow rate to produce the high flow rates associated with the product. The Oso Dualstream dramatically boosts the flow rate available to the hot and cold water taps by supplementing the mains flow rate with stored water in an accumulator.
 
Concept: The OSO Dualstream is a patented package the contains an OSO 20 series unvented cylinder and a cold water accumulator. The accumulator stores water in a butyl membrane and then delivers the water to the cylinder and the cold water pipework when demand exceeds the mains flow rate available.
 
The OSO cylinder is supplied as a fully flooded cylinder with the accumulator acting as an expansion vessel in addition to boosting the flow rate to the taps.
 
Performance: The OSO Dualstream will give performance unrivalled by any other water heating system. High flow rates to multiple outlets can guaranteed even with an incoming mains flow rate as low as 5 litres per minute.
 
OSO Dualstreams from 250 litres capacity are supplied with 1” hot and cold fittings to ensure the highest possible flow rate to the taps.
 
The OSO cylinder is supplied with a normal working pressure of 3.5 bar and an accumulator pre-charge of 2 bar. A 1.5bar pressure differential should be maintained at all times to maximize the performance of the system. The pressure differential should not exceed this figure as the accumulator lifespan will be shortened and the guarantee invalidated.
 
Sizes: Cylinder and Accumulator capacities of up to 380 and 450 litres respectively are available. System capacity is determined by the size and nature of the property and the performance of the mains water supply.
 
Dualstreams are most typically supplied in larger properties with cylinder capacities in excess of 200 litres, however packages are available from 120 litres.
 
Accumulator nominal capacities are usually larger than that of the cylinder, however to establish the correct size of the accumulator, the flow rate performance of the mains supply should be measured.
 
Installation: The Dualstream accumulator and cylinder can be installed either adjacent or remote from each other according to the nature and design of the property. If installed remotely, an additional expansion vessel should be connected to the system.
 
The Dualstream is supplied as a pre-plumbed package with connecting valves and pipework supplied with the product.
 
Further details on the OSO 20 series cylinder should be obtained from the 20 series product pages.