Best Solar Expansion Tank – Guide & Model 18 L Aquasystem
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🏆 What is the best solar expansion tank? Focus on the Aquasystem 18 L model
Solar energy is attracting more and more individuals and professionals. Installing a solar thermal system means benefiting from free, renewable, and environmentally friendly energy. But to ensure the safety and durability of your installation, the solar expansion tank is a key element that is often underestimated. So, how do you choose the best one? And why is the Aquasystem 18 L model a benchmark?
☀️ What is a solar expansion tank used for?
In a solar thermal circuit, the heat transfer fluid heats up strongly during the day, then cools down at night. This temperature variation causes the fluid to expand and contract . Without regulation, the pressure in the circuit would increase dangerously.
👉 The expansion tank absorbs these volume variations and keeps the pressure stable. It thus protects:
- the storage tank,
- solar collectors,
- the pipes,
- and the circulation pump.
A good expansion tank is therefore the guarantee of a more reliable and more durable system .
🔍 How to choose the best solar expansion tank?
Here are the main criteria to check before purchasing :
| Criteria | Why it is essential | To be checked |
|---|---|---|
| Capacity (volume) | It must be adapted to the total volume of the fluid in the circuit | 8 L to 35 L depending on the size of the installation |
| Maximum pressure | The vessel must withstand overpressure (often up to 10 bar) | Nominal pressure ≥ 6 bar |
| Temperature range | Solar fluid can reach over 100°C | Support up to +140°C recommended |
| Membrane type | It must be resistant to heat transfer fluids (glycol) | Special solar membrane |
| Manufacturing & reliability | A guarantee of safety and longevity | Recognized brand, manufacturer's warranty |
💡 Green-Négoce Tip: Avoid "classic heating" expansion tanks in solar circuits. Their membrane is not designed to withstand extreme temperatures or glycol fluids.
🔧 The 18 L Aquasystem solar expansion tank: an excellent compromise
On Green-Négoce.com , we have selected the Aquasystem 18 L model, renowned for its Italian manufacturing quality and robustness .
✅ Main technical characteristics:
- Capacity: 18 liters
- Working pressure: 10 bar
- Temperature range: –10°C to +140°C
- Membrane: special solar, resistant to heat transfer fluids (glycol)
- Made in: Italy
- Application: domestic and professional solar thermal installations
🌟 Its advantages:
- Designed for high temperatures of solar circuits
- Effectively protects against overpressure and thermal variations
- Easy installation and compact size
- Increased durability thanks to Aquasystem quality
- Excellent value for money
This 18 L model will be perfectly suited to the majority of domestic solar installations, particularly for systems comprising 2 to 3 solar collectors.
⚙️ Tips for a successful installation
- Position of the vase: install it on the return of the circuit, between the sensors and the tank, near the safety group.
- Pre-inflation pressure: adjust it according to the static pressure of the circuit (often between 1 and 1.5 bar).
- Annual check: check the pressure and condition of the membrane to avoid any loss of efficiency.
- Maintenance: Replace the vessel or membrane if the pressure no longer stabilizes.
💬 A properly sized and maintained vase means a more stable solar circuit and a longer lifespan for your entire system.
⚖️ Quick comparison: why choose Aquasystem?
| Brand | Ability | Max temperature | Max pressure | Average price | Advantage |
|---|---|---|---|---|---|
| Aquasystem (18 L) | 18 L | 140°C | 10 bar | 💶 Excellent | European manufacturing, reliable |
| Other brands on Amazon | 12 L | 120°C | 8 bar | 💶 | Volume too low |
| Other brand on Leroy Merlin | 25 L | 130°C | 6 bar | 💶💶 | High price, limited availability |
The Aquasystem 18 L model stands out for its balance between performance, quality and price , making it one of the best choices on the market.
🔗 Where to buy the best solar expansion tank?
Find the Aquasystem 18 L model directly in our store:
👉 Aquasystem 18 L solar expansion tank – Green-Négoce.com
Fast shipping from France, responsive customer service and personalized technical advice for your solar installation.
🏁 In summary
The best solar expansion tank is the one that guarantees the safety, performance and longevity of your installation. With its high-temperature solar membrane , its resistance to 10 bar and its European manufacture , the Aquasystem 18 L model meets all the criteria.
✅ Reliable, efficient and affordable — the ideal choice for your solar thermal system.