Hello and welcome to The Compost Bin. I'm Compostwoman and I live with my family in rural Herefordshire. We have nearly four acres of garden and woodland, all managed organically and to Permaculture principles, which we share with Chickens, Cats and assorted wildlife. We also grow a lot of our own food, run courses in all sorts of things and make a lot of compost!

I am a Master Composter and have spent more than a decade as a volunteer Community Compost adviser with Garden Organic and my local Council.
I'm a self employed Environmental Educator so I run workshops and events where I talk about compost, veg growing, chicken keeping, cooking, preserving and sustainable living. I also run crafts workshops and Forest School/outdoor play sessions in our wood.

We try to live a more self sufficient lifestyle here, as best we can, while still having a comfortable life and lots of fun.


To learn more about us click on the About Compostwoman tab and remember to click on the photos to make them full size!


Showing posts with label Hot composter. Show all posts
Showing posts with label Hot composter. Show all posts

Thursday, 16 August 2012

Hot Bin trial after 4 weeks - first sight behind the compost hatch!

Ok, so I have had the HotBin for just over four weeks. I took these photos on Day 30, first thing in the morning.

So far, I have been very impressed. The HotBin has "eaten"  many refills of material (more than 3 of them a week since the start) of mainly green waste (weeds, potato haulms, grass etc) since I got it.
 
Each time the level dropped down to a settled minimum and the internal temperature settled back down to around 40 C,   I refilled the HotBin to the top.  Obviously as time passed there was more material left in the bottom of the HotBin, so I could put less and less inside as there was less room. But I estimate I have put more than 800 l (ish) of waste, by volume, into the HotBin, which then worked to reduce this material down to coarse mulch consistency at the bottom of the HotBin. In four weeks.


By comparison, the Dalek bin has been refilled once during this period - so has taken roughly 500 l of material ( initial 330 l plus a refill of another 150 ish l)

I have had a bit of a problem with the external thermometer, but as I am getting the internal temperatures and as the material is disappearing at a rate of knots I guess I must be doing it correctly so I am not worried. HotBin are talking to me about this issue and I am getting a replacement soon.


Whenever I open the lid, there is steam and heat! As long as there is a fresh charge of waste to work on the HotBin has kept at a steady 55 - 65 C  inside - it usually takes 3 days for the temperature to drop to around 40 C - by which time the HotBin needs (and gets)  a refill.


But after four weeks the partially composted material was building up inside the HotBin, so I decided to open up the hatch and take a look, with a view to possibly removing any material which had composted enough.

I undid the two ratchet straps which help to hold the front hatch in place


having first put an old, split compost bag down to catch any material which I took out.


hatch open for the first time in 30 days!


I must admit I was surprised to see how well the material had already composted down.


Slugs on the inside of the hatch - they get everywhere!


As always my henny "helpers" appeared to see what was going on


See how much mulch grade compost has been produced! In a month! I removed 3 buckets full of material, it was rather wet and a bit coarse to use as compost just yet, but perfectly acceptable as a mulch and if put in another bin, would make good compost within another few weeks. Which is what I am going to do with it.

I did find it a little difficult to remove the material from the bottom of the bin for two reasons. I found it physically hard to get the stuff out because of the other material above it. I also was concerned about cutting into the bin itself with my spade.


The Hotbin, three quarters empty again, waiting for a refill.


Which it got, of all sorts of stuff including bindweed ( I love watching the bindweed cook and go black inside the HotBin!)




By comparison my (larger!) Dalek compost bin , filled at the same time, under the same conditions and with a mixture of the same material, had produced a very small quantity of mulch quality standard compost. But the rest of the material in the bin was not decomposed very much at all. I removed less than a quarter of a bucket of usable mulch compost in the bottom of the Dalek bin.






Now do not get me wrong, that is very good going for a Dalek compost bin, in high summer I expect to get usable mulch from one of these in around fourteen weeks - but not in four.

So - the HotBin is yet again really impressive. I put the material I removed from the bottom of the HotBin into the Dalek bin, and personally I think that is what I am most likely to use the HotBin for, as a very rapid means to process huge volumes of compostable material and convert it into a much smaller volume of mulch grade compost. This can then be either used or put into a Dalek or other compost bin to complete the process - if you want finer, more mature compost.

And by the end of my afternoon outside, the Hotbin had already reached 55 C internally. And by the next afternoon it was up to 68 C.

Truly a "Hot Bin"



Monday, 16 July 2012

HotBin trial - the first week.

 Ok, so I have had the HotBin in situ for just over a week. I took these photos on Day 9, first thing in the morning.

So far, I have been very impressed. The HotBin has "eaten" 4 refills of mainly green waste (weed, potato haulms, grass) this week. Each time the level had dropped down to about a quarter full - (about 50 L)  I refilled the HotBin to the top.  Which means the HotBin has consumed approx. about 600 ish L of waste, by volume, reducing this material down to coarse mulch ish consistency, now sitting in the bottom of the HotBin. In a week.

Even if I removed this partially composted coarse material from the bottom of the HotBin and left it to continue to compost down in the open (or in another bin!) , the HotBin would still have dealt with a staggering amount of material in a week compared with a conventional composting bin - so on throughput of material alone I am impressed.


Whenever I open the lid, there is steam and heat!




As long as there is a fresh charge of waste to work on The HotBin has kept at a steady 55 - 60 C  - it usually takes 3 days for the temperature to drop to less than 40 C - by which time the HotBin needs  a refill.





The Dalek, by comparison, has about 100 L of waste remaining in the bottom of the composter from the original 330 L of material I put into it a week ago. The temperature has dropped from a hot 65 C,  4 days ago, to a steady 30 C. This is really good work for a Dalek composter - I am impressed!  But it is time for me to refill the Dalek, so it can heat up and get going again.



I am going to transfer the partially composted material from the Hotbin into another, empty, Dalek composter - so I can continue to see exactly how much material the HotBin can eat in a week.

I am enjoying this! But then, I am Compostwoman...

Thursday, 12 July 2012

HotBin Trial Day 5 and 6 - with added Dalek!

Day 5, Tues 10th July 2012

12 pm
Ambient Temp 22 C



Hotbin had to be refilled to the brim as it had slumped to less than a quarter full and the internal temp has begun to drop rapidly to  less than 40 C - so I filled it up to the top with a mixture of weeds, grass and card, with a few handfuls of wood chips as bulking agent.


Found a slight issue when I tried to close the lid - if any debris gets on the flat surface...


The lid wont shut!



Easily fixed, though - just clear the debris away :-)




Dalek has slumped by 45 cm from the initial max fill level.




Internal temp in middle of surface layer 56 C - still working on initial charge of material.

Lots of steam.


Day 6
Wed 11 July 2012


Ambient Temp 18 C

Hotbin  has begun to warm up already. Level has significantly decreased since the refill yesterday/

 


 

Internal temp using probe, as before, in middle of surface - 46 C
Lid Temp 35 C


Dalek

Internal Temp in middle of surface layer 60 C
Internal temp at edge of surface layer 50 C

 Material slumped down by 50 cm from initial fill level.
Steaming and bin feels warm to touch from outside


 


Tuesday, 10 July 2012

HotBin Trial Days 2, 3 and 4

Day 1 (recap) Fri 6th July 2012

HotBin filled with a mixture of week old material from an existing compost bin, fresh weeds, cut nettles, hay and guinea pig droppings and paper scraps.



The ambient temperature was 18 Celsius when I filled the bin mid afternoon on a sunny but cool period during a showery day. After less than an hour the top temperature gauge read 40 Celsius ( reading the air temperature at the top of the HotBin) and the top layer of material inside the HotBin was at 25 Celsius.




Day 2 (recap)  Sat 7th July 2012

After 24 hours it had all slumped as the the material started to decompose.




After 24 hours the top layer of material was at 40 Celsius and the lid thermometer read 50 Celsius with an ambient temperature of 20 Celsius.

According to HotBin, this is a "textbook start"


Day 3 Sun 8th July 2012


Contents now steaming gently and when opening the lid I could feel a blast of warm air on my hands,
When taking readings the ambient temperature a cool 13 Celsius  and it was dull and rainy - not very summery weather!
Lid thermometer reading 45 Celsius.
Internal thermometer ( inserted about 10 -15 cm into material same reading regardless) at 50 Celsius.

Day 4 Mon 9th July 2012

11am.
LOTS of steam on opening the lid! Material slumped even more.


Internal temp at 60 Celsius!Yay!



Ambient temp. 16 C
Lid temp 48 C
Internal temp middle of box @ 10 cm down into material 60 C

(readings taken at 1100)


At 1800 the internal temp. was 65 C in the middle, @10 cm down and the internal temp. 2 cm from the edge, @10 cm down was 62 C.

It's hotting up in there!

Sunday, 8 July 2012

HotBin trial Day 1 and 2



When I was at the Masters Conference at Garden Organic I was very interested to see a new ( to me) design of hot composting bin.   Tony Callaghan was showing a new  product - the HotBin. HotBin are made in the UK and Tony  built his first prototype out of an old wheelie bin in his garden by going back to the basics of industrial composting engineering.

According to the HotBin website,
The HotBin is a simple design to help maximise what nature does by bringing together the right conditions to make hot composting easier. It is the bacteria decomposing the waste that generates the heat and the HotBin aims to keep them happy so you can enjoy fast successful composting. It does this by providing effective aeration between the bottom air inlet plate and the air outlet rotating valve, removing excess water through the valve as steam and allowing you to control the rate of heat loss.
I have been interested in this compost bin design for some months, ever since it was mentioned by Garden Organic in a Master Composters newsletter. I was also very impressed by the design when looking at it on display and when Tony from HotBin offered me one to try out, of course I said yes (as I said in my Hungry Bin post,  I never pass up the chance to experience something new involving composting and/or worms)

So when the courier arrived on Thursday with my new HotBin I was very pleased  and couldn't wait to get the system set up. Fortunately we had a dry and sunny day on Thursday so I was able to take lots of photos as well

The HotBin is a very well insulated black box with a lid, it is about the size of a wheelie bin and according to the manufacturer is made of expanded polypropylene and when empty weighs about 3 Kg.





It comes with a built in temperature gauge on the close fitting lid ( for measuring the heat at the top of the bin),  comprehensive instructions, a longer probe thermometer for measuring the heat in the working compost material, a "raking stick" a bag of bulking agent (composted wood chips) and a  "winter kick start heater" hot water bottle (empty plastic bottle which you can fill with hot water) 





I sited the HotBin what is rapidly becoming the "test" area, behind the barn- so I can feed it regularly and monitor the results.

What happens inside the HotBin is hot composting –dominated by bacteria – and ‘happy’ bacteria deliver fast successful composting. To keep the bacteria happy we need to provide the correct balance of HEAT, FOOD, OXYGEN and WATER

As the HotBin "Getting to 60 C "  FAQ says

Don’t worry, you do not need to understand all the science to get the best out of your HOTBIN. The HOTBIN is designed to help maximise what nature does and brings together the right conditions to make hot composting easy. All you need to do is check a few simple settings, add the minimum amount and good mix of waste and you should soon be hot composting. The common barrier to achieving the best performance of a HOTBIN is that the mix and volume of waste is not quite right. However, if your HOTBIN is hotter than ambient temperature it will still be working faster than a traditional compost bin.



The instructions for set up are an easy to read flowchart layout and say.
You may have enough traditional composting material readily available to get going straightaway; if so put it all into the HOTBIN, the more the merrier.
You may not have enough traditional composting material; be patient and build up you base layer when material becomes available. The temperature in your HOTBIN will build up more slowly until you have enough waste in your base layer.
Remember you can add kitchen peelings to the base layer at anytime.
A good base layer will also have easy to digest material that has been chopped up < 4cm to help the bacteria generate heat more quickly. Items like grass and chicken poop or pellets really help generate heat faster.

I obviously had enough traditional composting material available to more than half fill the HotBin, so got it going straight away. I used a mixture of week old material from an existing compost bin, fresh weeds, cut nettles, hay and guinea pig droppings and paper scraps.

I did not add any cooked food waste at this point as I did not have any, although I could have done so.




After 24 hours it had all slumped.






The ambient temperature was 18 Celsius when I filled the bin mid afternoon on a sunny but cool day. After less than an hour the top temperature gauge read 40 Celsius ( reading the air temperature at the top of the HotBin) and the top layer of material inside the HotBin was at 25 Celsius.

After 24 hours the top layer of material was at 40 Celsius and the lid thermometer read 50 Celsius with an ambient temperature of 20 Celsius.

After a couple of days, assuming I have followed the instructions correctly, I should expect to see a reading of 40 - 60 Celsius.

It was very easy to load the HotBin and so far I am impressed with the ease of use. I am also VERY impressed with the comprehensive and user friendly information on the HotBin website - especially the FAQ pages, which are full of all sorts of useful information about composting.

Let's see what the next few weeks bring!






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