Antifreeze towers are air circulation systems used to protect crops from spring frost, particularly in vineyards. With climate change, budburst is occurring earlier and young buds remain exposed to late frosts until the Ice Saints, making active protection essential.
To understand how the frost protection tower fits into a global strategy, you can also consult our dossier on protecting vines against frost.
What is an antifreeze tower?
An anti-freeze tower is a vertical device equipped with a powerful fan that stirs the air above crops to limit frost formation on buds and young leaves. This air movement reduces the damage caused by spring frosts, particularly in vineyards.
Depending on the model, the anti-freeze tower operates with a simple air circulation system, or incorporates an auxiliary heating system to reinforce protection when temperatures fall further. The aim is to secure harvest potential over several seasons, in a context where spring frosts are becoming more frequent and more damaging.
Antifreeze tower operation
The principle of the anti-freeze tower is relatively simple: a fan is installed several meters above the ground to stir and redistribute the air over a large area around the machine. The fan can be powered by an internal combustion engine fuelled by oil or gas, or by an electric motor, possibly coupled to a generator for remote plots.
Most anti-freeze towers can rotate 360° to cover concentric surfaces, with the option of limiting this movement to 180° or 90° depending on the terrain. The horizontal inclination of the air flow can be adjusted to adapt the height and reach of the air stream to the topography and height of the vegetation to be protected.
Radiative frost, advective frost and the role of heat
In a radiative frost situation, a temperature inversion is created during the night: the air is colder close to the ground and warmer a few meters above. The antifreeze tower will capture this warmer layer of air at altitude and bring it back down to bud level, saving 1 to 3°C depending on conditions and the presence of any auxiliary heating.
During an advective frost, the cold air is homogeneous over the entire height, and there is no longer any exploitable gradient. In this case, the antifreeze tower must be combined with an integrated or remote heat source to inject heat into the circulating air stream and maintain the temperature above the critical threshold for buds.
To better understand the difference between these types of frost and their impact on vines, please consult our article dedicated to spring frost.
Materials and design
Modern frost protection towers are built from corrosion-resistant materials such as galvanized steel, stainless steel or aluminum, to withstand repeated outdoor use over many years. The structure is dimensioned to withstand wind loads, rotational forces and the weight of the fan and any heating systems.
On the power side, an antifreeze tower can run on electricity, natural gas, propane or fuel oil, depending on the resources available on the farm and autonomy constraints. Solutions like VENTIGEL™ combine high-flow electric ventilation and on-board heating to effectively protect 2 to 3 hectares, during temperatures as low as -4°C.
Using the anti-freeze tower in the vineyard
Location and protected area
The sizing of an antifreeze tower park depends on the surface area to be protected, the frequency of frosts and the configuration of the terrain. A tower generally covers between 2 and 5 hectares, with optimum effectiveness when positioned in the center or slightly above the frost zone.
The layout must take into account :
- natural cold corridors;
- the presence of hedges, woodland or buildings that can block the air flow;
In large-scale operations, the combination of several carefully placed antifreeze towers can secure an entire vineyard or block of orchards.
Mobile antifreeze tower
Mobile anti-freeze tower models offer great flexibility, as they can be installed precisely in the most frosty plots and then put away at the end of the season. With a narrow chassis (often less than a meter wide) and a three-point linkage, they can easily be moved by tractor between the rows of vines.
Outside periods of frost, the mobile tower can be stored under cover, limiting visual impact on the landscape and protecting the equipment from bad weather, thus extending its lifespan. This mobility also makes it easier to share an antifreeze tower between several plots or between neighboring farms facing the same frost episodes.
Advantages of an antifreeze tower over other methods
Antifreeze towers offer a number of advantages over other frost protection solutions such as candles, heating wires or sprinkler systems.
Key benefits include
- Coverage of 2 to 5 hectares per tower, depending on model and conditions.
- a significant reduction in night-time logistics compared with candles, which have to be lit, monitored and extinguished.
- no water consumption, unlike sprinkling, which requires large volumes of water and specific installations.
- a more easily reproducible solution from one year to the next, with better controlled running costs in the case of electric systems like VENTIGELâ„¢.
To compare the antifreeze tower with other solutions available in the vineyard, please consult our page on vineyard antifreeze products.
Service life, maintenance and regulations
With its robust design and durable materials, a frost-free tower is designed to operate over many years, provided that regular maintenance is carried out. The main points to check are the rotating parts, lubrication, safety equipment, motorization and, where applicable, the heating system.
Depending on the area, the antifreeze tower may be subject to noise, height or landscape integration constraints, particularly in the vicinity of homes. Good anticipation of local procedures (town hall, appellation, neighborhood) enables the antifreeze tower to be installed under the best possible conditions, while preserving acceptability around the plots.
To place the use of antifreeze towers in the context of the vine’s annual cycle and the stages most susceptible to frost, you can also consult our article on the vine cycle.
