Insulating a compost bin

[sfitzger100]

Hi, Hope someone can help i have an unusual question.

I am trying to set up a hot compost heap and am using old wheelie bins I have to somehow insulate the wheelie bins and thought the thermawrap might do the trick. So that would be thermawrap inside/ outside the bin?

I know that I could use wood or buy a compost bin but this is for a masters university project I will not bore you anymore but I need to use this system i just need some help on how best to insulate it.

Would this work or is a complete waste of time and money.

Hope someone knows a bit more than me.

Thanks,

Sonya

 

[breezer]

if you must insulate it, dont bother on the inside, try bubble wrap on the ooutside.

how are you going to get compost from the bottom out?

 

[Thermo]

are you doing it as a hot bed to grow stuff in?

 

[sfitzger100]

Thanks for the replys,

Hi Breezer, Do you mind me asking, why do you think bubble wrap would work better on the outside? I had thought of that and its def the far cheaper way to do it. Do you know where I could find some more info on that?

Thanks.

Sonya

Hi Thermo,

This is just a way to test different blends of raw material carbon: Nitrogen ratios to see exactly what ratio will give the greatest heat over the longest period of time. The idea is that I can take the best blend of raw materials and then take that blend to a more complex insulated container.

I intend to drill a hole in the bottom of the wheelie bin and then put a perforated pipe through the hole with wooden slats above the pipe to passively aerate it. I will also turn the compost when the temperature begins to fall. The problem is that to get fast hot composting I have to have a decent amount of compost and as I have not the space in university to build 20 open compost heaps big enough to encourage hot composting so I need to insulate the wheelie bins somehow.

So I do not need to access the bottom of the bin as I will put all the ingredients in at the same time and will turn regularly then when the experiment is done I will move all the compost to a curing pile.

I hope that explains so any ideas on the insulation would be gratefully received.

Thanks,

Sonya

This should be do you think that

 

[JohnD]

A wheely bin is a fairly awkward shape to put insulation round. If you use something soft it will probably get damaged.

Could you use a double-skinned container (one inside the other) and pack the space between them, or inject expanding foam into it which will set rigid and improve the strength?

 

[sfitzger100]

Hi John D,

Thanks for the suggestion the only thing is I need to do the same thing to 20 bins to run the experiment so I need to try and keep it fairly simple and relatively simple. I will have a think about your suggestion and see if it can be done.

Thanks again for taking the time I really appreciate it.

Sonya

 

[JohnD]

If you can make or obtain rectangular boxes, you can use rigid polystyrene insulating board which is easily obtained in DIY sheds and builders merchants. It can be cut to shape with a breadknife or fine carpenters saw.

 

[Thermo]

im not sure your going to generate enough heat in the first place with a wheelie bin to get a good compost going. What size is it. they normally reckon on 1m3 being a minimum to really get the heat going

 

[JohnD]

A well-insulated one will heat up easily. I experimentally filled the polystyrene crate a big TV came in, with grass cuttings. It heated up and smelt awful.

 

[Thermo]

should have taken the tv out first!

 

[sfitzger100]

Hi,

Thanks very much for the suggestions. I did know that its better for the heap to be a metre cubed but I also know that if its insulated well it can be smaller than that. Its the insulation thats the trick.

Thanks for the info on the polystyrene as well thats interesting. The reflective foil I saw was the insulating equivilant of 63mm of polystyrene but was expensive about £18 for 6 metres.

Thanks again though its great to get some ideas.

Thanks,

Sonya

 

[Thermo]

straw was always traditionally used. that will be a cheap option. or bury them in the ground!

 

[sfitzger100]

Thanks Thermo,

I am very glad to have posted this question its given me loads to think about. Straw might work too. Cannot bury them as I think the University might be a bit peezed with me.

Thanks again,

Sonya

 

[Thermo]

How about making up a box from old pallets. Drop the bin into the middle and then fill in between with straw/polystyrene, bubblewrap etc etc

 

[ModernMaterials]

I think the earlier point (about insulating the bin on the outside) was a good one.

This way, the insulation is less likely to be damaged by your mixing (with a fork?)