I Transporting an Ice Cream Tub in hot weather

[cmb]

It was hot and I bought a tub of ice cream to take home.

I put the AC on and blew into the footwell where the ice cream was.

Was that sensible?

Is it better to let a static layer of cold air surround the tub of ice cream (say at -5C), or to blow cold (~+10C) air over it when the ambient in the car is ~+25C? What are the determining factors, and how would one crunch the numbers?

 

[berkeman]

As I see it, there are two options here:

1. Buy a small ice chest and some ice, and put the tub in the ice chest for the trip home. If this will happen regularly, start carrying a small ice chest with you at all times.
2. Eat the ice cream immediately, and then drive home.

I know which option I would have chosen...

 

[cmb]

1. Didn't know I was going to be buying any.
2. Can't eat 2kg of ice cream. No spoon, and slightly more than I usually eat in one sitting.
3. It was a physics question, not a question on shopping/culinary practicalities.

 

[berkeman]

Then use my option #1. Unless you have a source of cold air below freezing (like in your freezer), your best bet is insulation and adding ice.

 

[cmb]

I am not sure why you are persisting with that line. Neither was an option.

Which was best at the time, with blowing 10C air, or nothing? I am interested in what conditions can be considered to determine if an insulating layer of static air is better than flowing air, and what the factors are. This is a question about heat transportation, not ice cream and cars.

 

[Bystander]

I am interested in what conditions can be considered to determine if an insulating layer of static air is better than flowing air, and what the factors are.

What's your take on it? Ice cream at sub-zero, or "moving air at 10 C?" Which direction is the energy moving?

 

[marcusl]

I always keep a spare jacket and blanket in the trunk of my car (and a hat and gloves and boots...It can get cold here.) If I make an unexpected ice cream purchase in hot weather, I wrap it in the jacket and blanket. Seems to work well.

 

[cmb]

What's your take on it? Ice cream at sub-zero, or "moving air at 10 C?" Which direction is the energy moving?

There must be some point at which the flow rate is optimum. I mean, with the air completely static, diffusion into that 'air jacket' space from the 25C car will warm it up, whereas some movement of 10C air will displace the layer of cold air around the ice cream but avoid the diffusion of warm air around it.

I think best to wrap it in a plastic shopping bag to limit diffusion, and bathe the outside of the bag in cold air to reduce radiative exchange with the bag, which is basically what I tried to do (not a sealed bag though).