Need help for grade 7 heat project; make a thermos with houshold items

[Zett Vampyre]

Hi guys, this is my first post here, I hope to have fun here.

 

So, I need help with my grade 7 heat project, I need to make a thermos with a water bottle and other house hold items. The teacher will put hot water in each person's project, and after a certain period of time, will measure the temperature of the water, and the group with the warmest water wins. I'm thinking of wrapping the whole bottle with thick yarn first, put a layer of Styrofoam under the bottle, and cut a hole into two Styrofoam bowls and put packing peanuts/ newspaper balls in the bowls and taper the two bowls together and slide it over the bottle where the circle is. Then wrap the whole thing in foil and cling wrap. Is this a good idea?

 

All replies appreciated.

[Kaeroll]

Seems decent... I'd also recommend a nice thick layer of tinfoil around it.

[Zett Vampyre]

Thanks, I was planning on doing that.

[samtheflash82]

making a real "thermos" is going to be extremely difficult, if not impossible using household items. This is because a true thermos has 2 layers, the outer is a shiny, reflective layer to prevent radiant heat loss, the inner is an insulated layer to prevent conductive heat loss. Between the two is the tricky part; there is a vacuum to prevent convective heat loss. Creating a vacuum using household items is not feasible. Tell that to your teacher.

[Zett Vampyre]

I know. We just have to keep the liquid warmest for 5 min.

[insane_alien]

it doesn't NEED a vacuum, yes it would be good but its not going to happen.

 

the killer is going to be convection, do what you can to prevent air circulating inside the insulation. the second biggest factor is conduction. you'll want to have as little direct contact area with the inside chamber as possible(but without letting convection happen) and any contact should be done with low conductivity materials.

 

radiative heat transfer will be negligible so you don't have to make any shiny parts.

 

if you were dealing with liquid nitrogen or molten metal then yes, radiative heat transfer would be important.

[Zett Vampyre]

Will paper mache over the whole thing help?

[insane_alien]

perhaps as an outer casing

[Zett Vampyre]

Ya, I was thinking of that.

[Lovecraft]

If it's a test to keep the water hottest for 5 minutes, could you use a meterial that heats the water bottle via chemical reaction like a hand warmer?

 

That's what I'd do. I mean it's for 5 mins, not 24 hours. Is that cheating? It is a valid way of keeping the water hot, you are just putting energy into the system rather than trying to keep it from escaping in my scenario.

[insane_alien]

i think that would break the purpose of the challenge which is to provide the best insulation rather than who can stick a heater on it.

[Lovecraft]

Yeah, you are right, my other option of sticking the water bottle in a thermos probably defeats the purpose too.

[Zett Vampyre]

Yeah, you are right, my other option of sticking the water bottle in a thermos probably defeats the purpose too.

 

I thought of that too, and wrapping it in foil, but I was bored, so I decided I'll just build it to keep me busy.

[insane_alien]

foil won't do much. it can do stuff against thermal radiation but that is nowhere near your biggest heat loss vector.

 

foil doesn't really help slowdown conduction and convection.

[cameron marical]

try to make where the water is airtight, and try to make it so there isnt much air in it. i think thatd help.along with several compacted layers.

[TheSchoolHelper]

Well I'm doing the same project right now and our group has started the base of it.So we got a glass jar and first wrapped it around with tin foil.After that wrap that layer with black duct tape because it will absorb the heat. After that get duct tape and put cotton balls on it and put the thermos. You can put tin foil in side but that is a option. You can also put styrofoam inside.I would also recommend to put dead air inside so the heat can't escape. That is what I'm doing and I will message you my mark when I'm done with the thermos. I hope I helped a lot of people and Thanks.

[hermanntrude]

i'm concerned about the black duct tape. It will absorb the heat, you're right, but why do you want it to be absorbed? surely you want it to be NOT absorbed. You want the heat to stay in the water.

 

As was stated previously the most important thing is to prevent covection. Perhaps that can be done by ensuring there's no air inside?

[DrP]

The polystyene foam you mentioned sounds best to me. And as people have said above - stop air flowing in and out of the stytem.

[Phi for All]

I used to sell a radiant barrier for home attic insulation, and it was nothing more than reflective foil sandwiching a mylar center (the plastic kept the two sheets of foil from touching and conducting heat). We were told that (back then) this was how spacesuits were designed (but with several more layers).

 

I wonder how the results of the experiment would be if you simply wrapped a plastic bottle with aluminum foil (try not to wrinkle it too much), then did a layer of clear plastic wrap (Glad wrap), then another of tinfoil, more clear wrap and so on, until you have 7-10 layers? This would probably be the easiest and cheapest method if it worked well. You'd need to pay close attention to the mouth and lid, making sure they had just as much insulation.

[deadshot]

ok

 

 

how do you make a thermos and what supplies do you need

 

HHHHHHHHHHHHEEEEEEEEEEEEEEEELLLLLLLLLLLLLLLLLLLLLPPPPPPPPPPPPPPPPPPPPP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

 

 

MMMMMMMMMMMMMMMMMEEEEEEEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Abhay.K]

do try wrapping the bottle with wool, it helps in trapping heat

[EmCat334]

I have a grade 7 science project that requires this too. It's based on performance, appearance, and practicality. This is what I have so far:

 

 

Any advice? 

[Sensei]

42 minutes ago, EmCat334 said:

Any advice? 

Use styrofoam..

https://en.wikipedia.org/wiki/Polystyrene

Edited April 5 by Sensei