System Suggestion

The system solutions are only suggestions and may, of course, need adapting to your property, needs and conditions. The solutions are designed for 750 litre tanks, but the system can obviously be used with other models. We recommend you hire a professional (i.e. a plumber) to carry out the installation.

Dalatanken with pellet boiler and solar energy

Syst_Pellet_Sol_Dalatanken_Eng_Small              tank1
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The tank is the centre of the heating system. The boiler is connected such that it works on the tank's upper part, whilst the solar energy is used for the tank's lower part, via the solar energy coil. By adding an extra pair of valves, you can switch between letting the boiler heating up only the upper part of the tank, or the entire volume. (Winter and summer settings)
The boiler is controlled by a thermostat inside the tank that tells it when it needs to start up. As hot water rises, the heat from the solar energy coil at the bottom of the tank will heat up the entire volume once enough heat has been gathered from the sun. Therefore, the boiler will only start up if the solar energy is insufficient.

The heat to the radiators (or under floor heating) is provided by the tank through a bivalent bypass valve that first releases the hot water from the middle of the tank that has been mainly heated using solar energy. Once the heat from the middle begins to run out, the bypass engages and begins to mix in the heat from the top of the tank.

The hot water is prepared in two steps, using two gilled tube coils. By connecting the hot water socket with two mixing valves, the heat is first taken from the lower part of the tank (heated using solar energy), which enables the solar energy coil to proportion more heat to the tank. The lower the temperature around the solar energy coil, the bigger the temperature difference in the solar panels, resulting in a higher solar energy exchange.

The solution using the bivalent bypasses, double hot water coils and two cleverly connected mixing valves is a way to prioritise and make the most of the free energy provided by the sun and make savings by using less heat produced from purchased fuel.

Dalatanken with wood fired boiler and solar energy

Syst_Wood_Sol__Dalatanken_Eng_Small       tank2
Click on the image to enlarge.

The accumulator tank plays an important and central role when using wood fired burners. There is a legislative requirement that new installations should have an accumulator tank when using wood fired burners, but even existing installations benefit significantly from them with cleaner combustion, less pollution, improved effectiveness and, not least, much more comfort. Combining a wood fired system with solar energy results in a significant practical improvement, with likely savings of 20-25% in annual fuel volumes.

A wood fired system requires a significantly larger accumulator volume than a pellet boiler. A good system should be able to store enough energy for at least a day's use during the winter and the tanks should be able to receive at least the energy resulting from a full load of wood logs. Firing up the boiler more than once a day should only happen in exceptional circumstances.

The size of the boiler should also be suitable to enable you to fire up the tank between coming home from work and going to bed for the night. A modern boiler can do that with one or two loads of wood logs.
In almost all cases, the tank capacity should be at least 1,500 litres, although a higher capacity certainly won't hurt as the higher it is the larger the margins and the less often the boiler will need to be fired up.

We can provide tanks in most sizes, with the most common being the 750 litre tank. This is because it is often difficult to bring in larger tanks through the doors and corridors leading to the boiler room. The 750 litre tank has a diameter of 75 cm and will fit through most normal doors.

The system solution shows a combi installation that has wood firing, solar energy and a back up electrical option. The solution consists of a technical tank with coils for solar energy and hot water. This then connects to the number of slave tanks required to achieve the desired volume.

To get a "satisfactory" volume for the solar panels during the summer, the slave tanks can be switched off, or a directed valve can be installed that opens the connections between the tanks when the solar energy tank is fully heated. An even better option is to install a 4 coil tank instead of the split, 3 coil tank. This allows you to have the slave tank connected, yet still have usable hot water from solar energy, as it starts with the upper solar energy coil, heating the tank's upper part before activating the lower solar energy coil until all the tanks are fully heated.

The same principle holds for the hot water socket as in the pellet boiler above.

Dalatanken 4 coils

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The system for the 4 coil tank is the same as for our standard 3 coils tank. The difference is that it contains an extra solar energy coil in the upper part of the tank.

When the solar panels begin to work, there is naturally a delay before the temperature reaches a level where the hot water can be used. This is much quicker in the 4 coil tank as the solar energy is channelled to the upper coil and only once the water at the top of the tank is warm does the system switch and continue to heat the bottom part. Therefore, it is not necessary to wait until the entire tank has heated.

This solution is more economic the greater the capacity, as the volume is larger, with a longer heating time.

Further Connection Suggestions

Let the sun's energy heat the pool

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Kitchen boiler and solar energy

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Stocksbro Energi AB     SE - 783 92 Stora Skedvi     Tel +46 225 - 633 70     Fax +46 225 - 633 71
Expose 2010