Wind and magnets - what should you use?
We are often asked how strong a magnet should be if you want to use it to hang up a banner or curtain outdoors, for example, where it is windy.
We have contacted a sailing specialist and an engineer to help with the calculations, and based on their calculations about wind and weather conditions - including in particular the strength of the wind that can hit different materials under different weather conditions - we have created a table so that you have a guideline for your choice of magnets. Since we often have to calculate when setting up signs outdoors, we have chosen to focus on different wind strengths and how these can affect a banner made of fabric or tarpaulin.
NB! It is important to know that there may be additional factors that affect the choice of magnetic strength than just the strength of the wind, and therefore we have collected some examples and written below the table how to calculate your need for magnetic strength.
Wind strength table:
|
Wind strength / size |
Quiet |
Calm wind |
Weak wind |
Light vind |
Fair wind |
Strong wind |
Heavy wind |
|
0.5 m2 |
0.1 |
1.0 |
4.1 |
11.3 |
29.0 |
49.9 |
82.6 |
|
1 m2 |
0.2 |
2.0 |
8.2 |
22.7 |
58.0 |
99.9 |
165.1 |
|
1.5 m2 |
0.3 |
3.1 |
12.2 |
34.0 |
87.0 |
149.8 |
247.7 |
|
2 m2 |
0.5 |
4.1 |
16.3 |
45.3 |
116.0 |
199.8 |
330.2 |
|
2.5 m2 |
0.6 |
5.1 |
20.4 |
56.6 |
145.0 |
249.7 |
412.8 |
|
3 m2 |
0.7 |
6.1 |
24.5 |
68.0 |
174.0 |
299.7 |
495.4 |
|
3.5 m2 |
0.8 |
7.1 |
28.5 |
79.3 |
202.9 |
349.6 |
577.9 |
|
4 m2 |
0.9 |
8.2 |
32.6 |
90.6 |
231.9 |
399.6 |
660.5 |
How to read the table: The column to the left indicates the size of your sign or curtain. And the other columns show the impact in kgs. depending on the strength of the wind (calm/weak/strong), when the wind is directly on it fabric.
Example: You have a banner or curtain measuring 1.5 x 1.5 meters (3 m2), which must be able to withstand light winds. This gives a result of 68 kg. as a possible wind impact. Let's say that your curtain or banner weighs 2 kg. This must be added to the strength of the wind, which is why you need a magnetic strength of at least 70 kg. to be able to have your banner or curtain hanging magnetically. But if it can absorb water, the weight can easily more than double, and then you may need something like 75 kg.
The above is just a guideline
You should be aware that the above is just a guideline - wind does not always move in the same way, and a gust is difficult to calculate, as it depends on the surroundings, i.e. whether your banner or curtain is hanging in a sheltered position from wind and rain. Both can affect the result: whether the wind has free play to move around the fabric, and whether the fabric absorbs rain and therefore becomes heavier.
We always recommend that you choose safely so that you do not damage your banner or curtain solution. So an additional 20% in strength compared to the above calculations is not completely out of place.
In other words: choose a slightly larger magnet rather than choosing a short-term smaller saving.
Put up wind sail or sun sail on terrace or pergola
When you know what wind strength your wind sail must be able to withstand (first column in the table above), you can easily find out the strength you need to put up your wind fence or wind sail on the terrace, pergola or similar. And as a guideline, you should add 20% strength as described above, so that you take into account rain, etc., which makes the sail heavier.
Below you can see our best-selling magnets for magnetic installation of wind sails and sun sails in the garden etc.
Magnets on balconies
You can create many cool solutions with magnets on balconies, if your balcony has magnetic steel on the railing, ceiling, etc. However, we do not recommend hanging wind sails on balconies exclusively with magnets if you live in a multi-storey apartment building, as forgetting to take down the sail during a storm can catch the sail and send it flying around among the other buildings all too easily. However, it can be a good idea for balconies to secure the sail with strips or similar at the top and then use magnets to attach it to a metal railing below, so that it can be used as both a shade from wind and sun on the balcony.
