# How much dry ice should be used to keep this much dough frozen in a box of this size?

I would like build a package with frozen food products (to -18 °C). The products are small balls of pizza dough (diameter of 4 cm). Total dough ball weight is 10 kg (333 balls, 30 grams each).

I'm going to put them into a styrofoam package with dry ice (sealed and insulated) that has inner dimensions 33 x 23 x 28 cm and a wall thickness of 3.5 cm. The dough balls will be stored from 2 to 5 days.

The data for the dry ice:

• 16 mm granules
• Sublimation temperature: -78.5 °C
• Density: 1.1 - 1.4 g / cm^3

External temperature where the box is stored:
a) 10 °C.
b) 21 °C.

My question:

How much dry ice should I include to have all balls still frozen, i.e. have them in a temp. around -2°C, in the case when:

a) time of storage = 3 days
b) time of storage = 5 days

• I assume you're fine with a practical answer based on people's experience, rather than some kind of theoretical physical calculation? (You provided a lot of detail, and I'm not sure if that's just you being helpful (yay) or if it's because you want that kind of detail in an answer.)
– Cascabel
Commented Oct 21, 2014 at 18:27
• This is going to depend on the details of the packaging -- how thick the foam is, how well the lid is sealed (though some provision must be made for escaping CO2), what other insulation is around it, what surrounding conditions will be... (A good cooler can keep foods frozen for three days at summer temperatures just with normal ice, if everything starts frozen/prechilled and there is minimal air gap. A bad one under the same conditions would be doing well to last a day.) Commented Oct 22, 2014 at 0:34
• This looks like a homework question. In any event, this style of question seems more natural in the physics or engineering section than here. It is borderline science of cooking but definitely not food-science. Commented May 16, 2017 at 17:18