The solar radiator is a heating solution that is gaining ground. It uses the sun’s energy to heat your home. It’s a simple idea, but its operation is quite misunderstood. We will see together how it works, what are the different types, and why it could be a good idea for your home. The objective is to give you all the information to understand this system and see if the solar radiator is for you.

Key Points

• The solar radiator uses the sun’s thermal energy to heat a fluid, which then distributes the heat throughout your home.
• There are several types of solar radiators, such as water radiators, solar underfloor heating, or even Trombe walls.
• Adopting the solar radiator can reduce your energy bills and your environmental impact.
• Installation requires careful consideration of sensor orientation and system sizing for efficiency.
• The initial cost may seem high, but financial aid exists and the return on investment is often good in the long term.

Understanding how the solar radiator works

The solar radiator represents an innovative solution for domestic heating, exploiting a renewable and free energy source: the sun. It is essential to understand the basic principles and components involved to fully appreciate its potential and effectiveness.

The principle of solar thermal energy

Solar thermal energy is based on capturing solar radiation to produce heat. This heat can then be used directly for heating or for the production of domestic hot water. The principle is simple: the sun’s rays strike an absorbent surface, generally a solar thermal collector, which converts this energy into heat. This heat is then transferred to a heat transfer fluid, which transports it to a distribution system.

The essential components of a solar radiator system

A solar radiator system includes several key elements:

• Solar thermal collectors: They capture solar radiation and convert it into heat. There are different types of collectors, such as flat plate collectors and evacuated tube collectors, each with its own characteristics and performance.
• The storage tank: It stores the heat produced by the solar collectors, so that it can be used later, even in the absence of sun. The size of the tank depends on the heating and hot water needs of the dwelling.
• The circulator: It ensures the circulation of the heat transfer fluid between the solar collectors and the storage tank.
• The distribution system: It distributes the heat stored in the tank to the radiators or underfloor heating.
• An auxiliary system: Essential to ensure heating in case of insufficient sunshine. This can be a gas boiler, oil boiler, or an electric system.

The role of the heat transfer fluid in the solar radiator

The heat transfer fluid plays an essential role in heat transfer within the system. It is generally a mixture of water and antifreeze, or a synthetic fluid specially designed to withstand high temperatures and pressure variations. Its main function is to transport the heat captured by the solar panels to the storage tank, where it will be used to heat water or air. A good heat transfer fluid must have optimal thermal properties, such as high heat capacity and low viscosity, to maximize heat transfer efficiency. It must also be non-corrosive to preserve the durability of the equipment.

The choice of heat transfer fluid is crucial for the performance and longevity of the system. It is important to follow the manufacturer’s recommendations and carry out regular checks to ensure its good condition and effectiveness.

In summary, the solar radiator is a complex system that requires a good understanding of its operating principles and components to ensure efficient and sustainable hot water production.

Different types of solar radiators

There are several types of solar radiators, each with its own specificities and advantages. The choice will depend on your needs, your budget and the configuration of your home. Let’s discover together the main options available to best exploit solar thermal energy.

The solar water radiator

The solar water radiator is a classic radiator supplied with hot water heated by solar thermal panels. It is an effective solution for integrating solar energy into an existing central heating system. The heat transfer fluid circulates in the solar panels, absorbs heat from the sun, then transports it to the radiator, which diffuses it into the room. An auxiliary system, such as a boiler, is generally necessary for days when there is insufficient sunshine. This type of radiator can also be used for solar heating of your swimming pool.

Solar underfloor heating

Solar underfloor heating combines the advantages of underfloor heating and solar energy. Solar thermal panels heat a heat transfer fluid that circulates in a network of tubes integrated into the floor. This system provides gentle and homogeneous heat throughout the house.

Solar underfloor heating is particularly suitable for new constructions or major renovations, as it requires the integration of the heating system into the concrete slab.

It is important to properly size the system to ensure optimal efficiency. Underfloor heating is an increasingly popular solution.

Aerovoltaic solar panels

Aerovoltaic solar panels are hybrid devices that combine the functions of photovoltaic panels and solar thermal collectors. They produce both electricity and heat. The electricity can be used to power the electrical appliances in the house or be sold back to the grid. The heat, meanwhile, can be used to heat domestic hot water or for heating. These panels can also generate hot water in addition to electricity, thanks to cogeneration technologies.

• Combined production of electricity and heat
• Optimisation of roof space
• Reduced dependence on fossil fuels

The Trombe wall

The Trombe wall is a massive wall painted black, placed behind a glazed wall and oriented south. It captures solar heat and gradually releases it inside the dwelling by natural convection. This passive system is effective in improving the thermal comfort of buildings in winter while reducing energy consumption. It is particularly suitable for new homes and requires a specific architectural design. It is important to note that the Trombe wall is a passive solar energy solution.

Advantages and benefits of the solar radiator

Solar radiators offer a multitude of advantages, ranging from reduced energy costs to a positive environmental impact, not to mention improved thermal comfort. Let’s explore these benefits in detail.

Significant reduction in energy costs

One of the main assets of the solar radiator lies in its ability to significantly reduce energy expenditure. By exploiting solar energy, a free and abundant resource, you reduce your dependence on fossil fuels and traditional energy suppliers. This results in a notable decrease in your heating bills. A 2m² solar air collector can make a big difference.

Positive environmental impact and durability

The use of solar radiators actively contributes to environmental protection. By opting for this heating solution, you reduce your carbon footprint and participate in the fight against climate change.

• Reduction of greenhouse gas emissions.
• Use of renewable and clean energy.
• Reduced dependence on fossil fuels.

Solar energy is an inexhaustible and non-polluting resource. By investing in a solar radiator system, you make a responsible and sustainable choice for the future of our planet.

Optimal and homogeneous thermal comfort

Solar radiators offer superior thermal comfort thanks to a gentle and homogeneous heat diffusion throughout the room. Unlike traditional heating systems that can create uneven heat zones, the solar radiator ensures a constant and pleasant temperature. In addition, solar energy can heat homes and sanitary water.

Technical considerations for installing a solar radiator

The orientation and inclination of solar collectors

The orientation and inclination of solar collectors are determining factors for maximizing the capture of solar energy. In general, a due south orientation is ideal in the northern hemisphere. The optimal inclination depends on the latitude of the location and the main use of the system (heating or domestic hot water production).

• For heating, a steeper inclination (close to latitude + 10-15°) is preferable to optimize capture in winter.
• For domestic hot water, a shallower inclination (close to latitude – 10-15°) may be more suitable for more uniform production throughout the year.
• It is important to minimize shading from buildings, trees or other obstacles. A sunshine analysis is therefore essential.

A thorough study of the environment is necessary to determine the ideal orientation and inclination. Simulation tools can be used to evaluate the impact of different scenarios on energy production.

Integration into the existing heating system

The integration of a solar radiator into an existing heating system requires compatibility between the different components. It must be ensured that the solar system can work in synergy with the boiler or the heating system already in place. The installation of a combined solar system (SSC) allows for the production of both domestic hot water and heating.

• It is often necessary to install a buffer tank to store the heat produced by the solar collectors and redistribute it according to needs.
• The system regulation must be designed to optimize the use of solar energy and minimize the use of auxiliary energy.
• It is important to check the compatibility of the heat transfer fluids used in the different circuits.

System sizing for maximum efficiency

Correct system sizing is essential to ensure maximum efficiency and avoid energy waste. The heating needs of the building, the available surface area for solar collectors, and the local climate must be taken into account. INES has made available software called CalSol allowing the calculation of a certain number of parameters including the return on investment.

• The surface area of the solar collectors must be adapted to the heating and domestic hot water production needs. Too large a surface can lead to overheating in summer, while an insufficient surface can limit solar contribution in winter.
• The volume of the buffer tank must be sized according to the collector surface area and heat storage needs. Too small a volume can limit the system’s autonomy, while too large a volume can lead to heat losses.
• It is important to call on a qualified professional to carry out a thermal study and size the system optimally. Before installing a hybrid solar panel system, a qualified professional assesses energy needs and evaluates the project.

The solar radiator for domestic hot water production

Solar radiators are not limited to space heating. They can also be used for domestic hot water production, a particularly interesting application for reducing your dependence on fossil fuels and lowering your bills. Let’s explore together the different solutions available.

Individual solar water heater (CESI)

The individual solar water heater, or CESI, is a system designed specifically for domestic hot water production. It is an autonomous solution that can cover a significant part of your hot water needs, often up to 80% over the year, and even 100% during the summer months. The CESI is composed of solar thermal collectors, generally installed on the roof, and a storage tank where the water is heated. The heat transfer fluid circulates in the collectors, absorbs heat from the sun, and transfers it to the water in the tank via a heat exchanger. It is an effective way to use solar thermal energy to heat the water in your home.

Combined solar system (SSC)

The combined solar system (SSC) goes further than the CESI. Indeed, it ensures both the production of domestic hot water and the heating of your home. It can supply an underfloor heating system or water radiators, thus offering a complete solution to reduce your energy consumption. The SSC is particularly suitable for well-insulated homes and regions where heating needs are significant, as it optimizes the use of solar energy throughout the year. It is important to note that the system must be carefully sized to ensure maximum efficiency.

Optimising hot water consumption

To make the most of a solar radiator system dedicated to domestic hot water production, it is essential to optimize your consumption. Here are some tips:

• Choose water-saving sanitary equipment (taps, showers).
• Properly insulate hot water pipes to limit heat loss.
• Schedule your hot water production according to your actual needs.
• Regularly maintain your installation to ensure its proper functioning and durability.

Optimizing hot water consumption is a key element to maximize the benefits of a solar thermal system. By adopting responsible habits and ensuring the maintenance of your installation, you can significantly reduce your energy bill and contribute to environmental protection.

In conclusion, the solar radiator for domestic hot water production represents an ecological and economical solution to meet your hot water needs. Whether you opt for a CESI or an SSC, it is important to properly size your installation and optimize your consumption to fully enjoy the benefits of solar energy. Do not hesitate to call on a qualified professional to assist you in your project and benefit from personalized advice. Remember to check the aid available for the installation of solar thermal panels.

Alternatives to the solar thermal radiator

Although the solar thermal radiator represents an interesting solution for heating, other options allow solar energy to be exploited in a different way. These alternatives may be more suitable depending on the specific needs and constraints of each situation. Let’s explore these possibilities together.

Passive solar energy

Passive solar energy is a design approach that aims to maximize the use of solar energy for heating and lighting a building, without resorting to active mechanical systems. It relies on specific architectural principles and building materials to capture, store and distribute solar heat.

• Building orientation: Favour a south orientation to maximize sun exposure in winter.
• Use of materials with high thermal inertia: These materials, such as stone or concrete, absorb heat during the day and slowly release it during the night.
• Design of large south-facing windows: Allows maximum capture of solar light and heat.

Passive solar energy is a simple and effective solution for reducing the heating needs of a building. It requires careful design and a good understanding of building thermal principles.

Photovoltaic coupled with an electric radiator

This alternative consists of using photovoltaic solar panels to produce electricity, which then powers electric radiators. Although less direct than the solar thermal radiator, this approach offers great flexibility and allows the electricity produced to be used for other domestic purposes. It is important to note that the overall efficiency may be lower than that of a direct thermal system, but it offers increased versatility. This electricity can also be used to power underfloor heating.

Aerothermal heat pumps

Aerothermal heat pumps capture calories present in the outside air to heat a home. Even in cold weather, they can extract enough heat to ensure efficient heating. This system is particularly interesting because it can also serve as air conditioning in summer, thus offering a two-in-one solution. In addition, there are heat pump models compatible with existing radiators, which facilitates installation in already built buildings. Aerothermal energy represents a viable and increasingly popular alternative to solar thermal heating, particularly thanks to its versatility and energy efficiency. It is important to properly size the heat pump according to the heating needs of the dwelling and its insulation. Aerothermal heat pumps are an increasingly popular heating solution.

Cost and profitability of a solar radiator system

The initial investment and its components

The acquisition of a solar radiator system represents a significant initial investment. Several elements influence this cost, including the type of system chosen (solar water radiator, solar underfloor heating, etc.), the surface area of the solar thermal collectors required, the complexity of the installation and the cost of labour. The price of the buffer tank, which stores the hot water produced, must also be taken into account. For a 120 m² house, you should expect to pay around €15,000.

Available financial aid and subsidies

Fortunately, various financial aids and subsidies are available to lighten this investment. These include MaPrimeRénov’, the zero-interest eco-loan (éco-PTZ), and the reduced VAT rate (5.5% instead of the usual 20%) for energy renovation work carried out by an RGE-certified craftsman. These aids can significantly reduce the initial cost and accelerate the return on investment. Do not hesitate to inquire about the aid available for the installation of a new domestic heating system.

Long-term return on investment

Although the initial investment may seem high, it is important to consider the long-term return on investment. The energy savings made thanks to the solar radiator gradually offset this initial investment. The payback period depends on several factors, such as the size of the installation, the level of sunshine in the region, the price of energy and the financial aid obtained. Solar heating can become profitable in 5 to 7 years. In addition, the increase in property value due to the installation of an ecological system is a significant advantage. To accurately assess the return on investment, it is advisable to obtain several quotes from professionals and to use simulation tools such as CalSol.

Maintenance and durability of the solar radiator

The solar radiator, although designed for a long lifespan, requires regular maintenance to ensure optimal performance and increased durability. Careful monitoring and periodic interventions prevent breakdowns and maximize the energy efficiency of the system.

Regular maintenance operations

Regular maintenance is essential to ensure the proper functioning and longevity of your solar radiator system. Here are some operations to perform periodically:

• Visual inspection of solar collectors: Check for debris, leaves or dirt that could obstruct the surface and reduce solar absorption. Gentle cleaning with demineralized water can be carried out if necessary. It is important to use demineralized water to avoid limescale deposits.
• Heat transfer fluid check: Have the level and quality of the heat transfer fluid checked regularly by a professional. Degraded or insufficient fluid can lead to a drop in system performance.
• Circuit leak check: Inspect pipes, fittings and valves for possible leaks. Even a minor leak can lead to pressure loss and a decrease in system efficiency. Checking safety equipment is also important.

Regular maintenance by a qualified professional is strongly recommended to guarantee the safety and efficiency of your solar installation. A maintenance contract can be an advantageous solution to benefit from personalized monitoring and services adapted to your needs.

Lifespan of solar equipment

The lifespan of solar equipment is an important factor to consider when investing in a solar radiator system. In general, the main components have an estimated lifespan as follows:

• Solar thermal collectors: 20 to 30 years.
• Storage tank: 15 to 20 years.
• Circulation pump: 10 to 15 years.
• Solar controller: 10 to 15 years.

It is important to note that these lifespans are indicative and may vary depending on the quality of the equipment, climatic conditions and regularity of maintenance. Proper maintenance can significantly extend the lifespan of your solar equipment.

Warranties and after-sales services

When purchasing a solar radiator system, it is essential to fully understand the warranties offered by the manufacturer and installer. Warranties generally cover manufacturing defects and performance issues for a specified period. Make sure the warranty covers the main components of the system, such as solar collectors, storage tank and circulation pump.

It is also important to inquire about the after-sales services offered by the installer. Good after-sales service can ensure you receive quick and efficient assistance in case of a problem. Do not hesitate to ask for references and consult reviews from other customers before choosing your installer. It is important to avoid installation errors for increased durability.

The solar radiator in new construction projects

The integration of a solar radiator into a new construction project represents an opportunity to optimize the energy performance of the building from its design. This allows for a long-term ecological and economical heating system. It is important to consider the installation of solar heating from the outset.

Integration from architectural design

The integration of a solar radiator system must be considered from the first stages of architectural design. This allows for optimizing the orientation and inclination of solar collectors, as well as the arrangement of rooms to maximize the capture and distribution of solar heat. A well-thought-out bioclimatic design can significantly reduce the need for conventional heating. It is important to understand thermodynamics and geology for successful integration.

Regulatory and normative requirements

New constructions are subject to strict regulatory requirements regarding energy performance, particularly RE2020. The installation of a solar radiator system can help achieve these objectives by reducing energy consumption and greenhouse gas emissions. It is important to comply with current standards and to call on qualified professionals to ensure the conformity of the installation. For a new construction, the winning combination is a heat pump, solar panels and connected inertia radiators.

Optimisation of overall energy performance

The integration of a solar radiator into a new construction allows for the optimization of the building’s overall energy performance. By combining this system with other ecological solutions, such as reinforced insulation, double-flow mechanical ventilation (VMC) and high-efficiency energy equipment, it is possible to create a passive or positive energy house. This results in significant energy savings and optimal thermal comfort for occupants. It is important to carry out a thermal study before installation to assess your needs. The use of a heat transfer fluid is essential for heat transfer.

The solar radiator for specific applications

Solar radiators, although often considered for domestic heating and domestic hot water production, also find their place in more specific and sometimes less conventional applications. These applications take advantage of the flexibility and adaptability of solar thermal energy.

Solar pool heating

Solar pool heating is a common and effective application. It allows the swimming season to be extended at a lower energy cost. Solar collectors, often installed on the roof or near the pool, capture solar energy and transfer it to the pool water via a heat exchanger. This system is particularly interesting because it uses renewable energy and significantly reduces the costs associated with water heating. There are solar systems designed specifically for this application.

Systems for tertiary buildings

Tertiary buildings, such as offices, schools or hospitals, have significant energy needs, both for heating and air conditioning. The integration of solar radiators in these buildings can help reduce their environmental footprint and operating costs.

• Combined solar systems (SSC) can provide both heating and domestic hot water.
• Solar air conditioning solutions can be considered, using solar energy to power absorption or desiccant cooling systems.
• Precise system sizing is essential to meet the specific needs of the building and optimize its efficiency. It is important to choose your domestic heating carefully.

The integration of solar systems in tertiary buildings requires a thorough study of energy needs, architectural constraints and current regulations. A global approach, taking into account building insulation, the orientation of glazed surfaces and ventilation systems, is essential to guarantee optimal performance.

Solutions for less sunny geographical areas

Although sunshine is an important factor, solar radiators can also be used in less sunny geographical areas. Several strategies can optimize their performance in these conditions:

1. Use of high-performance solar collectors, capable of capturing even diffuse radiation.
2. System sizing taking into account periods of low sunshine and heating needs.
3. Integration of an auxiliary system, such as a condensing boiler or a heat pump, to ensure continuous heating even when solar energy is insufficient. It is possible to find suitable thermal systems.

In addition, building insulation plays a crucial role in reducing heating needs and optimizing the efficiency of the solar system. The combination of good insulation and a well-sized solar system can lead to significant energy savings, even in regions less favoured by the sun.

The solar radiator is great for very specific uses. Imagine heating your pool or a large building without spending a lot of money. It’s a clever solution that uses the sun. To find out more about how it works and if it’s right for you, visit our website now!

In summary

The solar radiator is a heating option that uses the sun’s energy. It’s a good idea for those who want to reduce their energy consumption and do something for the environment. We’ve seen how it works, the different types of systems, and what to consider before installing one. It’s true, the initial investment can be a bit high, but in the long term, it can really lower bills. And then, there’s aid for that. In short, it’s a solution to seriously consider for heating your home more sustainably.

Frequently Asked Questions

How does a solar radiator work?

A solar radiator uses the sun’s energy to heat your home. Special panels, often on the roof, capture the sun’s heat. This heat is then transferred to a liquid that circulates in your radiators or underfloor heating, thus warming your rooms. It’s an ecological and economical way to heat yourself.

What are the different types of solar radiators?

There are several types of solar radiators. The most common are those that use water heated by the sun to supply classic radiators or underfloor heating. There are also aerovoltaic panels that produce both electricity and heat, and the Trombe wall, a passive solution that stores the sun’s heat in a wall to diffuse it slowly.

What are the advantages of a solar radiator?

Installing a solar radiator reduces your energy bills because you use a free and inexhaustible source: the sun. It’s also good for the planet because it reduces your consumption of fossil fuels. Finally, these systems offer gentle and well-distributed heat, which makes your interior very comfortable.

What do you need to know to install a solar radiator?

For a good installation, you must first orient the solar panels well to the south and tilt them correctly to capture maximum sun. You must also ensure that the new system integrates well with your current heating. Finally, it is important to choose the right system size so that it is as efficient as possible for your home.

Can the solar radiator also produce hot water?

Yes, the sun can also heat your water! The individual solar water heater (CESI) uses solar energy to produce all the hot water you need. The combined solar system (SSC) goes further by heating both your water and your home. These solutions can significantly reduce your energy consumption for hot water.

Are there other ways to heat with the sun?

If the solar thermal radiator is not suitable for you, other options exist. Passive solar heating uses the design of your home (large windows, good materials) to capture the sun’s heat. You can also use photovoltaic panels to produce electricity that will power electric radiators. Aerothermal heat pumps are another alternative; they draw heat from the outside air.

How much does a solar radiator cost and is it profitable?

The initial investment for a solar system can be significant. However, there are financial aids, such as subsidies or tax credits, that can reduce this cost. In the long term, the savings made on your energy bills allow the installation to pay for itself. It is an investment that pays off over time.

What maintenance does a solar radiator require and what is its lifespan?

Solar systems are designed to last a long time. You just need to remember to do a little maintenance from time to time, such as cleaning the panels or checking the heat transfer fluid. Most solar equipment has a long lifespan, and manufacturers often offer good warranties to ensure your peace of mind.