What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

[Blazerdazer]

I have a project and I don't know how to do it. I need to make a thermos to keep water cold. What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

[zapatos]

1 hour ago, Blazerdazer said:

I have a project and I don't know how to do it. I need to make a thermos to keep water cold. What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

Wrap a bottle in insulation.

[Blazerdazer]

Thank you for the answer but what can I use for insulation?

[zapatos]

https://www.homedepot.com/p/Owens-Corning-R-13-Faced-Fiberglass-Insulation-Roll-15-in-x-32-ft-1-Roll-RF10/202585857

[iNow]

Yuck. Itchy.

I’d create two containers, a smaller one inside a larger one… wrap the inner edges with some foil then use high density spray foam insulation between them.

[zapatos]

OP was kind of light on details so I went for the easiest. Don't know if it is to used for drinking, or a contest measuring how long water stays cold, or the cheapest, or using things found in the home, or...

[iNow]

I assumed that’s where you were coming from. I mostly just have a conditioned dislike of pink batt fiberglass so got triggered 😝 

[exchemist]

3 hours ago, Blazerdazer said:

Thank you for the answer but what can I use for insulation?

Bubble wrap?

[Sensei]

6 hours ago, Blazerdazer said:

I have a project and I don't know how to do it. I need to make a thermos to keep water cold. What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

The easiest way to get the best score for this project is to use a 3D printer to make air gaps and connections between different layers.

Make a project, print, measure the time it's cool. Make the 2nd project, print, measure the time it is cool. Make the 3rd project, print, measure the time it is cool. etc. Pick up the best project to show to teachers.

Experiment with different filaments such as PLA, ABS, ASA, PETG, TPU, etc. and different 3D printing techniques. Create a precise spreadsheet to show the results.

Edited June 18 by Sensei

[KJW]

8 hours ago, Blazerdazer said:

I have a project and I don't know how to do it. I need to make a thermos to keep water cold. What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

You don't need to do anything. A thermos keeps hot things hot and cold things cold. Or do you need to make a thermos from scratch? If so, why? A thermos is basically a container inside another container with a vacuum in the space between the containers and the inner container having a mirrored surface.

 

 

[exchemist]

8 hours ago, Blazerdazer said:

I have a project and I don't know how to do it. I need to make a thermos to keep water cold. What can I do to make a thermos that can keep cold water cold for sometime? Can air be used as an insulator for this and how?

What I would do is get a large and a smaller polystyrene cup, perhaps from a coffee or cold drink dispenser, wrap the outer surface of the smaller one in aluminium foil (to reduce radiative heat transfer) then wrap that in bubble wrap, and put the whole lot into the bigger cup.  

[StringJunky]

1 hour ago, exchemist said:

What I would do is get a large and a smaller polystyrene cup, perhaps from a coffee or cold drink dispenser, wrap the outer surface of the smaller one in aluminium foil (to reduce radiative heat transfer) then wrap that in bubble wrap, and put the whole lot into the bigger cup.  

For a cold scenario, will the shiny side be best facing outwards?

[exchemist]

25 minutes ago, StringJunky said:

For a cold scenario, will the shiny side be best facing outwards?

Good point. I should think so, yes.

[swansont]

12 hours ago, Blazerdazer said:

Can air be used as an insulator for this and how?

Just in case you missed it, the suggestions you have been getting use air for insulation. A key is that the air doesn't circulate, so there's no convection. The solid material in insulation, bubble wrap and foam, etc. is for structural purposes (maintaining air pockets and possibly holding itself up)