| Comparison Between High Pressure and Low Pressure Systems |
|
High Pressure Systems |
Low Pressure Systems |
| Black & White Series |
Green & White Series |
Black & White Series |
Green & White Series |
Models Available
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50 Litres - 6 x 1.8m Tubes |
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| 100 Litres - 12 x 1.8m Tubes |
100 Litres - 10 x 1.8m Tubes |
100 Litres - 12 x 1.8m Tubes |
100 Litres - 10 x 1.8m Tubes |
| 150 Litres - 18 x 1.8m Tubes |
150 Litres - 15 x 1.8m Tubes |
150 Litres - 18 x 1.8m Tubes |
150 Litres - 15 x 1.8m Tubes |
| 200 Litres - 24 x 1.8m Tubes |
200 Litres - 20 x 1.8m Tubes |
200 Litres - 24 x 1.8m Tubes |
200 Litres - 20 x 1.8m Tubes |
| 250 Litres - 30 x 1.8m Tubes |
250 Litres - 25 x 1.8m Tubes |
250 Litres - 30 x 1.8m Tubes |
250 Litres - 25 x 1.8m Tubes |
| - |
300 Litres - 30 x 1.8m Tubes |
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300 Litres - 30 x 1.8m Tubes |
| Price |
A very low price for the quality but still in the more expensive class |
Around half the price of the high pressure system |
| Guarantee |
5 Years if installed according to specification |
2 Years if installed according to specification |
5 Years if installed according to specification |
2 Years if installed according to specification |
Choice
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If you want to keep your municipal or pressure pump pressure, a high pressure system is the best choice. You will have less available hot water compared to the low pressure systems. |
If you want a cheap system that works very good the low pressure system is the best choice. But keep in mind if there are 15mm pipes in the wall when you want a 22mm stream at the tap. Mixer taps will restrict flow substantially |
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| The Tank |
| Outer tank material & insulation |
Both the high pressure and the low pressure tanks are the same. |
| Heat retention |
Because the tank is closed, heat retention is better than the low pressure system |
There is a breather in the tank which causes more heat loss than with a high pressure system |
| Inner tank material |
1.2mm Stainless steel tank |
1.2mm Stainless steel tank |
0.4mm Stainless steel tank |
0.3mm Stainless steel tank |
| Weight |
These tanks are heavier and can weigh up to 50kg |
These tanks are lighter and easier to install and can go up to 40kg |
| Magnesium Anode |
These is exactly the same. As with any other geyser, regular replacement of the anode makes the geyser last much longer because it reduces rust substantially |
| Pressure |
600kpa |
500kpa |
Designed to use as gravitational pressure from the water level in or above the tank. All air vent should be open. |
| The Evacuated Tubes |
| This is a standard 1800mm length x 58mm diameter x 2mm thick glass tube that is being used. This tubes is designed to withstand 37mm diameter hailstones. |
| Heat pipe inserts |
Heat pipe tube inserts is present in a high pressure system. This pipe is filled with a low boiling point fluid that causes an effective heat transfer cycle. |
There is no heat pipe inserts present in a low pressure system as the water form tank also circulates the inner glass tubes. |
| Water inside the tube |
There is no water present inside a high pressure tube as it is filled with the above mentioned heat pipe insert which gather the hear form the black inner tubes and transfer the heat into the tank. |
Inside the tubes water is present where the heat energy is transferred directly to the water inside the tubes. |
| The Stand |
| These stands are very similar in both low pressure and high pressure system. |
| From 50L systems to 150L systems |
This stand is black in colour |
This stand is green in colour |
This stand is black in colour |
This stand is green in colour |
| Four cross braces at the back of the stand (under the geyser) and two cross braces at the front of the geyser and one cross brace on each side. Six of these cross braces is the same length where as the two longer braces will be used for each side. With the beam for the plastic cups for the glass tubes situated at the bottom of the stand. |
Four cross braces at the back of the stand - two short cross braces and two longer braces. Two longer cross braces at the front under the tubes (same length as the back pair). Two longer cross braces will be placed on each side. With the beam for the plastic cups for the glass tubes situated at the bottom of the stand. |
Four cross braces at the back of the stand (under the geyser) and two cross braces at the front of the geyser and one cross brace on each side. Six of these cross braces is the same length where as the two longer braces will be used for each side. With the beam for the plastic cups for the glass tubes with heat pipes. |
Four cross braces at the back of the stand - two short cross braces and two longer braces. Two longer cross braces at the front under the tubes (same length as the back pair). Two longer cross braces will be placed on each side. With the beam for the plastic cups for the glass tubes situated at the bottom of the stand. |
| From 200L systems to 300L systems |
This stand is black in colour |
This stand is green in colour |
This stand is black in colour |
This stand is green colour |
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| Roof strengthening |
These stands are well designed so that the mass is spread among the feet which means that there is a relatively small load per foot. |
| Electric Backup System |
| This is optional with any solar geyser system. A standard South African electric element is being used and can be controlled with either a thermostat or a SR609 which will be explained bellow. |
| The SR609 Electronic Control Panel |
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This is a fully programmable switch. It features:
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The current water temperature.
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The time.
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It can be set to heat the water in the tank electrically in three cycles of time and temperatures.
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Default: if the water is cooler than 54oC between 4 and 5 am, the water will be heated to 60oC. The same happens between 5 and 10pm again.
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A manual button raises the temperature up to the programmed temperature (usually 60oC), whenever needed.
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There is a battery backup, so it will not forget its settings.
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Disadvantages
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To keep the pressure, a litre of cold water must replace every litre of hot water used. This means that the water temperature comes down as water gets used. |
If both the outer and inner tubes break, the water in the tank will run out. This very seldom happens. The system will only work if all the tubes are installed, or if the holes of the broken tubes are plugged. |
| The more expensive one of the high pressure systems |
More expensive than a low pressure system but more affordable than the Black and White Series |
The water pressure is lower at the outlets then the pressure obtained with a high pressure system |
