Heated food container

[GedsJeep]

. I have been looking at the insulated food bags that takeaways use and thinking how inefficient they are.

I'm looking to build a removable heated box to go in the back of my car.

I already have the box, a large plastic one from IKEA or some such which I am going to insulate with bubble wrap and survival blanket to reflect the heat.

What I could do with is some sort of 12 volt gel pads which could heat the box up To a decent level that would keep the food warm for up to 30 minutes.

Now there are heated bags on the market but they are either not big enough or prohibitively expensive.

Does anyone know of a cheap ish element that could maintain a decent temperature in an insulated 3 foot by 2 foot by 2 foot box?


Cheers

[greasemonkey]

So your going to want to be hitting around 60 or 65 degrees C? Somewhere around there.
I don't really know, but what crossed my mind was some kind of heat emitting bulb.

I remember seeing a slow cooker, or a pressure cooker somewhere, with a bulb doing the heating. Can't seem to find any reference to it now. Anyway, it wasn't 12 volt.

[photoman290]

try a local pharmacy. the  cool bags  drugs come in should work the other way round. they usually just throw them away.

[oakwoodtv]

All you need is a hay box.

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

[Chug]

this any good Ged?

http://www.amazon.co.uk/Coolbox-Electric-Warm-Cool-Box/dp/B003UZ83WE

[Julian]

this any good Ged?

http://www.amazon.co.uk/Coolbox-Electric-Warm-Cool-Box/dp/B003UZ83WE

I've got one of those.  Very good, but only drop/heat so many degrees below/above ambient as they use a peltier cell.

Great for days out and camping (if you have a mains hook up) but are quite noisy to sleep close to in a small tent.

[Jamesrl]

What about a 3d printer hot bed, good for 110°C  when plug into a cig lighter socket.

http://www.ebay.co.uk/itm/12V-24V-3D-Printer-Heatbed-MK2B-PCB-Hot-Plate-Heat-Bed-for-RepRap-Prusa-Mendel-/141618065952?hash=item20f9183220:m:mOoq57Cex2un1Cj58kJVlAQ

[RichardP]

If your Ikea box doesn't work out then try and get your hands on an Army Norwegian food container, would take minimal heat to keep anything hot in them.

http://www.ebay.co.uk/itm/18-litre-Norwegian-Food-Container-Ex-Army-Cool-Box-Hot-Box-10-sqn-sqms-/161855117747?hash=item25af5119b3:g:jGkAAOSwhcJWGrHH

[GedsJeep]

this any good Ged?

http://www.amazon.co.uk/Coolbox-Electric-Warm-Cool-Box/dp/B003UZ83WE

i thought of that , but its too small mate. i can go out with up to 10 deliveries at a time.

What about a 3d printer hot bed, good for 110°C  when plug into a cig lighter socket.

http://www.ebay.co.uk/itm/12V-24V-3D-Printer-Heatbed-MK2B-PCB-Hot-Plate-Heat-Bed-for-RepRap-Prusa-Mendel-/141618065952?hash=item20f9183220:m:mOoq57Cex2un1Cj58kJVlAQ

i looked at these and reptile heat pads. the printer ones get too hot and the problem with both is that they provide contact heat only, the rest of the box is unaffected.

If your Ikea box doesn't work out then try and get your hands on an Army Norwegian food container, would take minimal heat to keep anything hot in them.

http://www.ebay.co.uk/itm/18-litre-Norwegian-Food-Container-Ex-Army-Cool-Box-Hot-Box-10-sqn-sqms-/161855117747?hash=item25af5119b3:g:jGkAAOSwhcJWGrHH

again, its the size.

its an akward problem

[photoman290]

have you tried nichrome wire? stick it inside some silicone tubing and wrap it around the inside of the box sealing it down with silicone sealant? i have  both silicone tubing and nichrome wire. also got an insulated box as well. i suppose i will have to do the experiment then

[GedsJeep]

i always said i liked you........

so, what exactly is it?

[photoman290]

i always said i liked you........

so, what exactly is it
 
nichrome wire is what used to be used on big light dimmers before silicon. and heating elements as well. i need a bit more info. what voltage? assume 12 volts from the fag lighter. think the max current is 30 amps but not sure on that. thats 390 watts. a bit high.  will have to buy a curry as well ' and see what wattage keeps it hot for 30 minutes. aren’t you coming down here soon? i am about an hour from newquay if you want to drop round for a chat and a cuppa. i can give you all the bits then as well.

[GedsJeep]

i am, im down there next week ( sat onwards )

i think as this will be transferred to different vehicles that 15 - 20 amps would be better?

Cheers

Ged

[Jamesrl]

What about a 3d printer hot bed, good for 110°C  when plug into a cig lighter

Are yes but with a bit of giggery pokery you can have it full adjustable from ambient to 110°c thermostatically controled to +/- 0.5°C.

You can also get'm in flexible silicon 12v or 24v.

[knighty]

if the food is already hot, and the box is insulated then you won't need much heat to stop the food cooling down

12v silicone 3d printer mat would keep the box good at hot


personally, I think I'd use a 24v mat, (still feed it 12v) so the heating is a bit more tame and it draws less amps