Would Sky Lanterns still fly in below freezing temperatures?
The physic principle of sky lanterns
Sky Laanterns are based on a physic principle that hot air is lighter then cold air and therefore the heat produced by the fuel cell and stored inside the lantern lift it in to the sky.
Based on our previous experience, we noticed that when sky lanterns are used in low temperature they require less time to fill up with hot air and release them free.
Sky lanterns are based on the physic principle that the fuel cell produces hot air which expands and becomes lighter than cold air. In fact, during the summer months in hoter countries (35+ C), the lanterns require longer time to bring the internal temperature of the lantern above the environment temperature.
Have said that, sky lanterns is one of those things that you got to have in a storage cabinet or cupboard and if the weather allows, you and your guests will have an unforgettable and magical experience.
On the other hand, if the weather conditions are not suitable, you must postpone the lauch to another date and ensure that you fully enjoy them and safely execute the launch of the lanterns.
To safely and securely release sky lanterns, please read the instruction and guidelines on our insert or you can get more information by visiting our Flying Sky Lanterns page where each sky lantern design is explained in more details. The video below show the preparation of a traditional Chinese SkyLanterns but the physic principle remain the same for all sky lanterns designs. Video Sky lanterns Instructions
Optimum weather conditions to launch sky lanterns
The optimum weather condition to use sky lanterns is when the wind speed is below 5 mph 8 kmh, low humidity, high atmosphere pressure and low temperature.
If the wind is too strong, it becomes difficult to keep the lantern steady while it is filling up with hot air. Also, if the wind squashes the lanterns all hot air produced by the fuel cell is expelled from the base and it will need to refill again.
It is preferable that after checking the wind direction find a place protected by a wall, fence or a line of trees and bushes. In this way, you will have the time to get the lantern filled with hot air and once released, it will immediately fly away from the wall or bushes which gave you protection from the wind.
Sky lanterns are made with paper and the fuel cell is calibrated to lift the weight of the paper and the bamboo ring. As soon as the lantern is removed from its packaging, the paper will quickly absorb the humidity from the environment.
If the lanterns becomes heavier because high humidity level, the heat power produced by the burning fuel cell might not have enough power to dry the paper and lift the lanterns to the sky. For this reason, we suggest keeping them in their plastic wrapping till the point of use and good quality sky lanterns, like Premium or Supreme designs have a bag of silica gel to absorb humidity while in storage and till it is used.
High pressure is generally associated with clear sky, few clouds, low wind speed and low humidity level, perfect for sky lanterns!
Instead, low pressure brings rain and wind. However, lower is the pressure heavier is the air and therefore the fuel cell requires more heat to lift the same weight.
On the other hand, higher is the atmospheric pressure, cleaner will be the air, consequently the lantern will require less time to fill up with hot air and gently it will rise in to the sky.
As mentioned above, when using sky lanterns in low temperature, the fuel cell will require less time to fill the lantern with hot air.
To conclude, it is important that you use your own judgement to establish if the weather conditions are suitable for sky lanterns. For first time users, we also suggest trying a couple of sky lanterns on two different evenings before the date of your celebration, This will help you to familiarise with the sky lantern and understand the best place where to do the collective launch.
On the day of the event, just before you distribute the lanterns to your guests, it would be preferable to demonstrate to other first time users how to use it. Meanwhile, you will test the weather conditions and ensure that everyone will enjoy it.
Last but not least, the overall quality and the materials used to build the sky lanterns have huge differences on the performance and reliability of the product itself.
On our website, each sky lanterns design (Supreme - Premium - Chinese - Traditional) is explained in details with the list of material used to build them.
In brief, as any other product, some are good and others not as good. E.g. if you test drive two cars, like a Lamborghini HURACÁN and a Fiat 500, they both can go from point A to point B, however the performance, comfort and speed of a Fiat simply cannot reach those of a Lamborghini.
We hope the information provided will help you to clarify some doubts which you might had. More importantly, we wish that the information and guidelines will help sky lanterns lovers to make an informed decision on how and when safely to use flying sky lanterns and securely releasing them in the sky.
Please let us know if you have any other question and we will be happy to help. We can also offer Technical Support on site for parties and events. click here for more info.