Why choose a Dualstream system?
- No cistern in the loft - no risk of water stagnation, Legionella and frost damage
- Greater plumbing designs, uses less pipe-work, saving time and money
- Wholesome water to all cold taps and balanced hot and cold water supplies
- Dualstream utilises one of the slimmest and highest volume yielding unvented cylinders on the market
- Will provide a substantial increase in water volume, to both hot and cold-water outlets, with-in the building
- Will work at very low flow rates (9 l/mm) 1 Bar (min Water Board supply requirements)
- Sized correctly the system will fill any number of baths simultaneously and ideal for multi-bathroom dwellings
- True 'power shower' performance without the need of pumps
- Overcomes problems associated with low mains pressure or inadequate flow rates
- Efficient insulation, low power consumption. All unvented cylinders are insulated with high density CFC free insulation.
- Can replace the need for high maintenance noisy break tanks and booster pump sets
- Accumulators and cylinders can be linked together for greater demands, for the larger properties, small hotels and leisure and sports clubs
- Indirect Models from 125 - 500 litres (heated from a boiler source)
- Direct Models from 125 - 500 litres (heated from electric immersion)
- Accumulator models from 100 - 500 litres
- Twin coil cylinders available on request
- Immersion heater upgrades available
- Unvented stainless steel cylinders up to 300 litres with 25 year warranty
- All electrical components are covered by 2 year warranty
- Accumulators have longest industry warranty at 5 years
The Dualstream System
The Dualstream systems by GAH Heating Products have been developed as an advanced
solution for domestic hot and cold water installations. A Dualstream system will increase
the water volume and maintain the mains pressure to both the hot and cold supplies, even when more than one outlet is in use at the same time.
Dualstream has been designed to function on the minimum standard for domestic water
supply as provided by local water authorities - which is 1 Bar at 9 litres per minute.
GAH offer full technical assistance and design service to enable the optimum Dualstream
system to be configured to overcome situations where poor mains supply and pressure
are considered a problem.
How the Dualstream system works
The system mainly comprises:- an unvented direct or indirect cylinder, an accumulator
(cold water storage vessel), a combination valve and an expansion relief valve.
The accumulator has an internal controlled butyl diaphragm, incoming cold water is
stored within this diaphragm at mains pressure. The air space between the diaphragm
and the accumulator case is pressurised, this balances the supply and maintains
pressure to the unvented hot water cylinder and cold outlets. When hot and cold water
outlets are turned on the stored water from the accumulator supplements water from the
incoming main, this results in consistent pressure and flow to all taps, showers and baths
even when outlets are used simultaneously. Pressure will be sustained for as long as the
accumulator is holding suffficient volume of water.
Please View the PDF Below for more Information

|
TDD 200-125 |
|
|
The code number refers to the cylinder sizes TDD 200-125 (Model code TDD = Direct), 200 litre accumulator followed by 125 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
125 |
¾ |
|
|
150 min |
3kW+3kW |
70°C |
650 |
755 |
955 |
|
505 |
265 |
|
138 |
|
|
|
|
|
TDD 200-210 |
|
|
The code number refers to the cylinder sizes TDD 200-210 (Model code TDD = Direct), 200 litre accumulator followed by 210 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
200 |
¾ |
|
|
240 min |
3kW+3kW |
70°C |
940 |
1230 |
1475 |
|
505 |
265 |
|
220 |
|
|
|
|
|
TDD 240-150 |
|
|
The code number refers to the cylinder sizes TDD 240-150 (Model code TDD = Direct), 240 litre accumulator followed by 150 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
150 |
¾ |
|
|
175 min |
3kW+3kW |
70°C |
790 |
915 |
1155 |
|
505 |
265 |
|
164 |
|
|
|
|
|
TDD 300-210 |
|
|
The code number refers to the cylinder sizes TDD 300-210 (Model code TDD = Direct), 300 litre accumulator followed by 210 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
200 |
¾ |
|
|
240 min |
3kW+3kW |
70°C |
940 |
1230 |
1475 |
|
505 |
265 |
|
220 |
|
|
|
|
|
TDD 300-300 |
|
|
The code number refers to the cylinder sizes TDD 300-300 (Model code TDD = Direct), 300 litre accumulator followed by 300 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
300 |
¾ |
|
|
350 min |
3kW+3kW |
70°C |
1215 |
1555 |
1790 |
|
560 |
275 |
|
331 |
|
|
|
|
|
TDD 500-300 |
|
|
The code number refers to the cylinder sizes TDD 500-300 (Model code TDD = Direct), 500 litre accumulator followed by 300 litre hot water cylinder.
|
Storage Capacity (litres) |
inlet/outlet size (inches) |
Coil Surface (m² ) |
Coil Rating (kW) |
Reheat Time (∆T=50° C) |
Element Power |
Max. temp. |
Dimensions in mm |
Weight full (kg) |
|
A |
B |
C |
D |
E |
F |
G |
|
300 |
¾ |
|
|
350 min | | |