FAQ solar energy
- What are the advantages of solar energy?
Solar energy is a natural auxiliary energy:
- silent and non-polluting (no impact on the environment)
- free and economical
- it can be used easily for lasting heat comfort in summer and winter, with extra heating provided by another energy if necessary: electricity, gas, fuel oil or other energies.
It can also reduce CO² emissions and thus combat the greenhouse effect and global warming.
- What energy savings can I expect from a solar installation?
This depends on many criteria (direction of the panels, climatic conditions, etc.). You can obtain more detailed information from your local installer.
- Does the solar installation work if the weather is not sunny?
Yes, absolutely: even with cloud cover, energy from the sun is recovered by the solar installation. This energy is not sufficient, but savings are still made. You must ensure that the panels are facing due south without any shadow being cast by trees or buildings.
- Must the solar installation be switched off during a long absence?
No. The station must remain powered up; only the electric heater can be switched off.
This means that the safety systems for preventing overheating can be activated. In countries with high insolation, it is recommended that the panels be covered to prevent this situation.
Questions about the solar water heater
- What does a solar water heater comprise?
A solar water heater features three elements: the collectors, the tank and the solar station.
- What is the average lifetime of a solar water heater?
It is the same as an electric water heater, namely 10 to 15 years.
- What is the temperature of the mixing valve and its function?
The temperature mixing valve at the output of the tank is preset to 50°C in the factory. It can be reset from 45 to 65°C. It is a safety valve for the user, and prevents very hot water above 65°C from being supplied.
- Is it necessary to overdesign a solar water heater with respect to a conventional electric water heater?
This depends on the country, the insolation, habits of using hot water and the operation of the electric heater or boiler.
Within the context of operating on night-time electricity in areas of moderate insolation, solar water heaters must be overdesigned.
Important note: the surface of the collectors must be overdesigned to prevent any early malfunction and/or ageing.
Questions about the collectors:
- How do the collectors work?
The collectors absorb the energy of the sun's rays and supply it in the form of heat. This heat raises the temperature of a heat transmitting fluid, which circulates from the sensors to a water storage tank and passes through a solar station (closed circuit).
- What is the average lifetime of the collectors?
More than 15 years.
- What type of collectors does Atlantic use?
The solar collectors of the Atlantic range are high yield flat collectors featuring a high-strength glass with a low level of iron and an absorber with a high absorption power for improved recovery of energy.
- What are the installation conditions of the collectors so as to increase energy savings?
The energy coverage rate of a solar water heater depends chiefly on:
1) The orientation of the house: the best orientation for solar collectors if directly south.
2) Solar mask: these are the shadows cast by a building, a tree or a wall that mask the sensors from the sun.
3) The number of collectors installed (depending on the insulation rate). However, care must be taken to avoid overheating: if the number of panels is overdesigned, the overall installation will be damaged.
4) The inclination of the panel that depends on the location of the country with respect to the equator (e.g. the ideal value for France is 45°), but performances are hardly affected at all if the inclination is greater than 15°.
- How frequently do the collectors have to be cleaned?
They do not have to be cleaned, as the glass is self-cleaning. In extremely polluted regions or areas of sandy or dusty wind, they can be cleaned with a just a cloth once a year to remove any dust, but this is not mandatory.
- What do you recommend if snow covers the collectors?
We recommend that you do nothing: the collector can bear the snow, which will have a tendency to slide on the glass. The snow will melt rapidly as soon as a black section is exposed.
- What are the risks in extreme weather (storms and hail)?
The strength of the sensors complies with the technical notices of the organisation (CSTB) that approves all roofing and attachment elements. ATLANTIC’s systems are designed to resist extreme weather. The instructions of the manuals must be followed, in particular concerning the ballasting of the panels on frames.
- Is there a risk of burning related to collectors on frames (children playing nearby)?
There is a risk with regard to the connection, but they must be insulated. The energy recovered heats the metal parts. We recommend placing the panels out of the reach of children. For any operations carried out on the panels, it is essential to take the necessary safety measure (gloves, checking the temperature of the panels, etc.).
- Can the Twin-Tubes (optional accessories) be buried for a frame installation, for example?
Yes, but in a PVC type conduit.
Questions about the solar station:
- How does the solar station work?
The solar station is the real nerve centre of the installation. It manages the installation and controls the operation of the pump designed to transfer the heat absorbed by the collectors to the tank.
- If the collectors overheat, can the safety relief valve evacuate the vaporisation of glycol?
No. The safety relief valve only operates in the event of collector malfunction (faulty expansion vessel, flow pressure too high). The normal pressure is 3 bars. In the event of boiling, it is the expansion vessel that receives the coolant liquid.
- In which situations is glycol vaporised?
Glycol is vaporised in the event of strong insolation, with little or no water drawn. It can also be vaporised if the installation is poorly designed (tank volume/collector surface ratio).
Operation in the event of boiling of the collector:
o When the tank is at 65°C, the heat regulation stops the pump.
o The collector can rise to 120°C. In this case, the pump is started up and the tank is allowed to rise to 80°C.
o When the tank is at the maximum of 80°C, the pump is stopped and in this case, the collector can rise in T°.
o Toward 140°, it starts boiling and the glycol is vaporised. The entire content enters the expansion vessel, which is designed for this purpose.
o To prevent the installation from emptying each time it reaches the boiling point, it is prohibited to fit an automatic bleed that is not isolated by a valve at the outlet of the sensor.
o Once vaporised, the collector can rise up to 200°C.
o At the end of the insolation, the collector condenses and the liquid returns.
- Does the heat transmitting fluid have to be replaced every 2 years?
No, it only has to be checked every 2 years to verify the quality of the antifreeze and its anti-corrosion quality. If it has boiled many times owing to a poorly designed installation, the fluid can become acidic and damage the installation.
- If a problem with the station arises, does the station have to be entirely replaced?
Each component of the station can be removed easily and replaced.
- Is there a fault indicator?
No, only the regulation display can be used to monitor any faults on the LCD screen.
Technical questions on the installation
- Are any special tools required to install the system (special wrenches, etc.)?
The solar installation must be fitted by a professional. The system is assembled with a standard set of tools. However, wrenches must be provided.
- Does the installation have to be rinsed before it is filled with glycol?
Yes, it must be rinsed. The rinsing must be carried out exclusively with the coolant fluid used for the filling.
- Are there any water heater/collector links included in the Atlantic Packs?
No, the links are accessories (Twin Tubes).
Atlantic supplies a set of tubes up to the passage of the roof.
- The solar water heater pack contains all the material, including the coolant fluid and the thermostatic mixing valve, depending on the models.
Apart from some references, the safety valve protecting against overpressure in the tank is not generally provided. Please consult us to obtain more information.
- The collector pack comprises all the material mounted on the roof, including 1 m of connection hose (to pass through the roof), the bleed, and the sensor with 1 m of cable.
Only the ventilation hole tiles are absent for the roof models.
Between these elements, a connection must be made using Twin Tubes (easy but expensive solution) or conventionally by using copper insulated by the installer.
- Can the solar seals be used again after the first tightening?
It is advisable to change the seals if the installation has been in operation.
- Can the system be installed outside of the habitable volume?
Yes, for example in sheltered room such as a garage type or a thermal facility on a terrace.
In Northern countries or ones with a temperate climate, we recommend that the piping be insulated to enable the best possible recovery of energy.
- Can an automatic bleed be fitted instead of the manual bleed supplied with the collectors?
An automatic bleed at the top of the installation can be a source of major problems in the event of boiling. Some of the glycol could be evacuated from the system (risk of additional overheating and damage to the installation). Using a specific solar automatic bleed involves fitting a bleed isolation valve. The valve must be closed after filling and setting the mode.
This FAQ is not exhaustive. If you did not find an answer to your questions, please feel free to contact our after-sales service. We will reply as soon as we can.