Simple and Effective Unheated Greenhouse Protection with Thermitube
Unheated Greenhouse and Frost Protection: Passive Safety with Thermitube
Maintaining an unheated greenhouse is the cornerstone of winter and spring agricultural production. In the face of increasingly frequent and intense climate events, horticulture and market gardening professionals are looking for reliable, durable and cost-effective frost protection solutions.
Thermitube is the bioclimatic solution that transforms your existing structure into a self-regulating thermal system. Using the remarkable thermal inertia of water, this passive device captures solar energy during the day and releases it at night. It maintains a stable environment inside your unheated greenhouse without consuming any external energy. To reduce the risk of frost and crop loss, choose Thermitube’s natural and high-performance frost protection.
Can an unheated greenhouse withstand white frost and black frost? Understand the risks to better protect your unheated greenhouse
An effective frost protection strategy starts with recognizing the two main types of frost events. Each one causes damage through different mechanisms.
White frost (or radiation frost)
White frost (or radiation frost) occurs through radiative cooling. It happens during calm, clear, windless nights. Heat stored in the soil and plants is gradually released into the atmosphere. When surface temperatures drop below 0°C, water vapor condenses into frost on plant surfaces. This phenomenon is precisely what threatens an unheated greenhouse, especially if it lacks an adequate protection system.
To effectively maintain an unheated greenhouse, the Thermitube solution relies on a simple yet powerful physical principle. By radiating the heat accumulated in the soil and tubes during the day, Thermitube creates a radiative effect that prevents the surface temperature of leaves from dropping below the freezing dew point. This mechanism offsets heat loss caused by nighttime radiation, providing ideal passive protection for any unheated greenhouse.
Thanks to this process, Thermitube offers a reliable and cost-effective response to localized white frost events, helping to keep your unheated greenhouse safe without relying on energy-intensive heating systems. It’s a durable and efficient solution to protect cold-sensitive crops in an unheated greenhouse, even on the coldest nights.
Black frost (or advection frost)
Black frost is formidable. It is caused by a mass of very cold, dry air (advection). Because the air is dry, frost does not form, and there is no release of latent heat. The cold penetrates directly and rapidly into plant tissues, causing damage and blackening. Since the cold air sinks, the greatest risk is within the lowest 80 cm of the greenhouse, which directly threatens any poorly protected unheated greenhouse.
Thermitube’s reinforced protection: faced with this dry, renewing cold, Thermitube uses its water mass as a large thermal battery. Heat is spread by convection to warm the air and by direct radiation onto the plants. The system generates enough energy to raise temperatures by a few degrees, thereby ensuring an unheated greenhouse remains protected even under extreme conditions. The system is especially effective in the lower part of the greenhouse, where an unheated greenhouse is most vulnerable.
The Thermitube Principle for an Unheated Greenhouse: The Bioclimatic Thermal Accumulator
The secret of Thermitube’s efficiency lies in the simple and clever use of the physics of water and solar energy.
Operation and Thermal Performance of the Unheated Greenhouse
Passive Daytime Storage: Flexible black tubes absorb the light and thermal spectrum of the sun. Water has the highest specific heat capacity of all common substances, allowing it to store a massive amount of heat, which is essential for maintaining an unheated greenhouse. This energy is “stored” for use during the night.
Guaranteed Nighttime Release: When air temperature drops and the surrounding air becomes colder than the water, the water releases energy by radiation directly onto the crops and by convection to warm the air in the area. It also heats the soil through conduction, thereby ensuring protection of the unheated greenhouse during cold nights.
Keeping Your Unheated Greenhouse Frost-Free Across Different French Climates
Solar radiation is low in winter and increases in spring.
December and January: These two months are the least sunny and the coldest of the year.
Mid-February, March, and early April: Sunshine increases and the climate warms up, helping maintain an unheated greenhouse more easily.
Winters are short and often dry, but plants are vulnerable to advection frosts and thermal shocks.
Throughout the winter, Thermitube greatly reduces the risk of frost in the greenhouse when combined with a P17, thermal screen, or inflatable double wall.
These regions experience significant temperature variations and cold winters with a high risk of late frosts and black frosts.
In December/January, the risk of frost is greatly reduced if the Thermitube is combined with a double P 30. Insulation with a P17 or a screen is not sufficient.
The climate is characterized by mild winters but an increased risk of sudden, short-lived spring frosts and black frosts.
Throughout the winter, Thermitube greatly reduces the risk of frost in the greenhouse when combined with a P17, thermal screen, or inflatable double wall. A P30 provides even better performance.
Comparison of Frost Protection Solutions for Unheated Greenhouses: Thermitube vs. Alternative Techniques
Choosing the best solution to keep your greenhouse frost-free requires a comparative analysis of the available options. Thermitube stands out for its passive nature and versatility.
Advantages and Disadvantages of Alternatives
Technique Alternative | Advantages | Disadvantages |
|---|---|---|
Active Heating (Calorifère, Aérotherme) | Maximum efficiency, precise setpoint control. | Massive and variable operating costs (gas/fuel oil/electricity), heavy carbon footprint, complex maintenance. |
Sprinkler system (Frost protection irrigation) | Highly effective against radiation frost, uses latent heat. | Enormous water resource, ineffective against strong winds (black frost), risk of breakdown, flooding, and need for 24-hour monitoring. |
Thermal Screens/Shades (P17, P30, Forcing) | Low investment cost, easy to install. | Low temperature gain (maximum for P30), cannot withstand severe frosts, requires labor for daily opening/closing. |
Candles/Heaters (Local heating) | Rapid, local heat, instant heat. | Very high operating costs (paraffin), smoke emissions (pollution and phytosanitary risk), labor-intensive nighttime lighting/extinguishing. |
Thermitube (Hydro-accumulateur)
| 100% Passive, Zero Operating Costs, Proven Reduction in Freezing Risk | Requires sufficient daylight to recharge, more effective in a well-insulated greenhouse. |
The Decisive Advantage of Passive Frost Protection for Your Unheated Greenhouse
Choosing Thermitube means investing in the long-term viability of your business.
Investment and Durability: Winter Security for Your Unheated Greenhouse
Profitability and Financial Support
The low installation cost, combined with zero operating expenses, guarantees a rapid Return on Investment (ROI), often between 2 and 5 years. Additionally, Thermitube is a key piece of equipment for the energy transition in agriculture and benefits from several support programs.
We assist you in preparing your subsidy application to help you maximize your investment in your unheated greenhouse.
Logistics Simplicity
Thermitube is easy to install (unrolling, filling with water, sealing) and has a long lifespan (7 to 10 years). Positioned close to the plants, it optimizes space without reducing usable area.
Don’t wait for the next frost. Secure your unheated greenhouse now.
