We are often asked why dry ice produces a large amount of fog when water is poured over it. The answer is quite simple, and it’s something that can be a lot of fun to experiment with! The fog that is created comprises heavy water vapor and sublimated CO2. This vapor is even heavy enough to settle into the bottom of a container, making for a cool and spooky special effect. Creating fog with dry ice is perfect for evoking a frightening feeling on Halloween, adding a dramatic flair when shooting photography or turning that garage band performance into a concert-quality event.
We decided to do some tests and see just how long we could extend our dry ice fog effect. Based on several tests both indoors and outdoors, we were able to make two pounds of dry ice generate a whopping 20 minutes worth of steady fog! We catalogued the variables and here are four tips that can help you replicate our results and maximize fog created with Penguin Brand™ Dry Ice:
1. The ideal “water to dry ice ratio” to create fog effects is about one half gallon per pound of dry ice.
Using the right amount of water will help maximize the fog. For example, when using two pounds of dry ice, you should add at least one gallon of water. Ideally, you want to use a thick, rectangular chunk of dry ice and a bowl large enough so that the water submerges the dry ice to a depth of about half an inch.
2. Use a heavy plastic bowl, three times as deep as the thickness of the dry ice you’re using.
One of the key challenges of generating fog with dry ice is balancing fog amount and thickness. A simple way to do this is to use a bowl deep enough to allow the fog to pool before it spreads out.
3. Use a small fan to direct the fog.
For both indoor and outdoor use, dry ice fog dissipates about three feet from the source. To maximize the range of the effect, utilize a small fan on a low setting to direct the fog.
4. Cycle the water as often as possible.
This tip has the largest impact on the duration of the fog. If you have a set-up where you can circulate the water on a regular basis, you’ll be able to keep the reaction going longer. If you allow the water to stagnate, the amount of carbonation infused in the water will decrease the amount of fog you can generate.
Using dry ice for effects is never an exact science, but these tips will help you create the most fog for the greatest impact. If you need to know where to buy dry ice, try our store locator.It is important to note that although the fog is just water and C02, you should always allow for adequate ventilation when using dry ice.