Styrofoam coolers are small, cheap and easily disposed of and can be great for a variety of uses. But how long does ice last in a styrofoam cooler and is it the best option for you?
Water ice will last 12-24 hours in a styrofoam cooler, with larger coolers able to hold ice for longer if completely filled. Dry ice stored in a styrofoam cooler will last approximately 18-24 hours before it completely disappears.
Depending on the size of your styrofoam cooler and how much ice you use will determine how long that ice lasts. There are also different things you can do to make the ice last longer in your cooler.
How Long Does Regular Water Ice Last In a Styrofoam Cooler?
Regular water ice will last around 12-24 hours in a styrofoam cooler. Most styrofoam coolers are thin (0.25-1 inches) and don't offer a huge amount of insulating ability.
Most styrofoam coolers are small and thus having only a small amount of ice leads to ice melting faster.
Below you can see a video of an ice test I did with a small 5-Quart Coleman FlipLid cooler. This cooler is plastic with styrofoam insulation. You can see that it lasts less than 24 hours when completely filled with ice.
If you were to only partially fill the cooler, as most people do, the the ice wouldn't even last this long.
In fact, if you're just using a small amount of ice or frozen water bottles/ice bricks then you may only get 4-6 hours of ice retention from a styrofoam cooler.
However, if you have a large styrofoam cooler and you use a large amount of ice then your ice will last much longer than 24 hours, especially if your cooler is kept in a cool and shady place.
The below video shows someone using a larger styrofoam cooler and filling it with just 15 lbs of ice. They get over 3 days of ice retention in their styrofoam cooler. If they filled the cooler to capacity I would have expected approximately 4-6 days of ice retention.
So it really depends on the circumstances, the size of the cooler as well as how much ice you use.
How Long Does Dry Ice Last In a Styrofoam Cooler?
Dry ice is commonly used in styrofoam coolers for food deliveries, especially for frozen foods like meats and premade meals. This is because the dry ice can keep the food completely frozen and the styrofoam coolers are cheap and disposable so these companies can leave the cooler with the customer and not worry about needing to retrieve it.
Dry ice is frozen carbon dioxide and it is approximately -109 degrees Fahrenheit. It doesn't melt like water but instead sublimates or turns into a gas. This leaves no wet mess around.
Again, how long dry ice lasts in a styrofoam cooler depends primarily on how much dry ice is used and how big and thick the styrofoam cooler is.
Most companies use small blocks of dry ice in relatively small coolers. In these cases the dry ice will last approximately 18-24 hours.
If more dry ice is used then it can last as long as 3+ days. The more dry ice you use and the thicker the styrofoam cooler the longer the dry ice will last.
How Do Styrofoam Coolers Keep Ice Cold?
Styrofoam is a brand name for extruded polystyrene, however “styrofoam coolers” are actually made from expanded polystyrene which isn't as dense and likely isn't made by the Styrofoam brand. It's just the word we use to describe the product.
Styrofoam is melted down and then put through a blowing agent which injects billions of tiny air bubbles into the mixture before it is formed into the shape of the cooler.
These coolers are actually 95% air and it is these little air pockets that create the majority of the insulation in the cooler.
Heat struggles to move through air, especially when those air pockets are separated from each other like they are in styrofoam coolers. This works as a great insulator and stops heat moving from the outside air into the cold contents of your cooler.
Are Styrofoam The Best Coolers For Keeping Ice?
While styrofoam coolers are good insulators they are not the best coolers for keeping ice the longest.
The high-end roto-molded coolers like Yeti, Pelican and brands like Otterbox can hold ice for 3-4 days easily and can even hold ice for up to 14+ days.
This is because these coolers use polyurethane which is a more effective insulator. However, it is heavier and more expensive and the high-end coolers use 2-3 inches of insulation in the walls of their coolers whereas styrofoam coolers generally have less than 1 inch of insulation in the walls and lid of their cooler.
What Are The Benefits of Using Styrofoam Coolers?
There are a few major benefits to using styrofoam coolers over other types of coolers.
Cheap – This is one of the main reasons. Styrofoam coolers are cheap and easy to manufacture in bulk. You can see them for as little as $10 or less on Amazon which is incredibly cheap compared to expensive coolers like Yeti.
Disposable – Because they are cheap they are able to be used for a single use or just a couple of times and then be disposed of without a major financial loss.
Can be made into many shapes – For companies selling and distributing products you can get styrofoam coolers made in different shapes and sizes to suit your needs.
Lightweight – Styrofoam coolers are the lightest coolers on the market (except maybe bubble wrap) which makes them good for shipping as you can pay less fees because there is less weight.
The Problems With Styrofoam Coolers
Styrofoam coolers aren't perfect and there are some problems with them.
Not durable – These coolers are not durable at all and don't last very long. They can easily break, snap, get dented or have pieces break off them.
Not the best ice retention – The ice retention is ok, but it's not amazing.
Create waste – While they technically can be recycled the fact that they are 95% air and they tend to absorb food and other stains means they aren't cost effective to recycle. This adds to land fill and creates waste.
Where To Buy Styrofoam Coolers
Styrofoam coolers are easy to buy and are available from lots of different stores, both online and in person.
One of the easiest places to buy them in from Amazon. They have a wide range of shapes, sizes and different price points.
This is the best place to go to. buy just a single styrofoam cooler or if you're just buying a few
If you're looking to buy in bulk for commercial purposes then your best best is to get in contact with companies that specialize in making shipping boxes and styrofoam containers.
You can get bulk discounts and can get the exact size and shape you need for your business.