Hot Composting to heat greenhouse for winter.

iamtony

Hi I'm wondering if anyone has done this successfully ive been making a Compost pile in an old wheelie bin and I've 3 more to fill. I've the temperature up to 30 degrees inside it since two days ago using leaves, fresh grass clipping and pond water and poo from the filter.
My plan is to get the three going at different times so one should have heat in it. They take up alot of space inside the greenhouse so I'd like to pump water through pipes that pass through the bins and run it to a bath of water inside.
Nothing is concrete at the moment so open to suggestions from anyone who has successfully done it.

The Continental Op

Don't think you'll have enough mass?

But as I'm sure you are aware there is nothing new in what you are trying.

One way it used to be done https://www.heligan.com/news/the-story-of-the-10000-pineapple (and some more info on that particular link file:///D:/Nick/Downloads/34-Article%20Text-109-1-10-20151018.pdf).

Then there's composting woodchips to heat water https://www.instructables.com/Compost-Heating-System/ which now I have a woodchipper I'm thinking about.

iamtony

So I'm not sure how clear that image is, the temp kept rising to 36° today so it will be interesting to see if it hit 40° tomorrow. That's my goal.
I have that bin inside the greenhouse at the moment so hopefully it keeps the chill out while I try keep these things growing.

iamtony

I've also added some lighting today which makes it look cool

And im converting and old snake tank with heat mat and heat lamp to start seeds.

blackbox

iamtony wrote: »

Hi I'm wondering if anyone has done this successfully ive been making a Compost pile in an old wheelie bin and I've 3 more to fill. I've the temperature up to 30 degrees inside it since two days ago using leaves, fresh grass clipping and pond water and poo from the filter.
My plan is to get the three going at different times so one should have heat in it. They take up alot of space inside the greenhouse so I'd like to pump water through pipes that pass through the bins and run it to a bath of water inside.
Nothing is concrete at the moment so open to suggestions from anyone who has successfully done it.

I wouldn't bother with the circulation system. It might save some space, but it might also cool the compost too much.

iamtony

blackbox wrote: »

I wouldn't bother with the circulation system. It might save some space, but it might also cool the compost too much.

Yeah I was thinking it might steal the heat alright. I'm just playing around with different ideas the main goal is to stop any freezing. I'm gonna insulate with bubble wrap soon and hopefully that with the compost bin inside it will keep a steady temperature.
I'm just curious if anyone has actually done this successfully

Turbulent Bill

Do you have enough material to keep the compost bins 'fuelled' over winter? A fixed amount of decaying material gives out a fixed amount of thermal energy. Depending on the insulation, solar gain in the greenhouse etc., you could get low-temp, long duration heat output or the opposite.

How do you find the compost thermometer? Might give one a go myself.

iamtony

Turbulent Bill wrote: »

Do you have enough material to keep the compost bins 'fuelled' over winter? A fixed amount of decaying material gives out a fixed amount of thermal energy. Depending on the insulation, solar gain in the greenhouse etc., you could get low-temp, long duration heat output or the opposite.

How do you find the compost thermometer? Might give one a go myself.

it's very handy. It's exactly like the food one except longer. Temp of the compost was 38° when I turned out the lights at 10 tonight.
The compost is simply fallen leaves and cut grass all chopped up with the lawn mower. Then i cleaned my pond pump sponge in a bucket of pond water and poured that in and in 2 days it heated up thst much.
From reading online if you see grass with lots of leaves on it and cut the grass and leaves its almost the perfect ratio of carbon to nitrogen. I've very tempted to bring my wheelie bin and lawn mover to the park at the end of the road to cut some strips
I've honestly no idea how long each bin is going to hold heat before it's actually made the compost. With proper hot composting the pile gets up to 65° and makes the compost is about a month so we will see how hot mine gets with a bit less bulk than the recommended 1 meter squared.
Its a fun little project and hopefully I'll get a nice amount of compost out of it if nothing else.
Regarding having enough fuel if I can't get grass and good stock of leaves i can try other materials like cardboard and food scraps but thats a good bit more work chopping it up to size.

CelticRambler

I'll be following this thread to hear how you get on!

While I've toyed with this idea over the last few years, you're ahead of me in getting the "infrastructure" in place. So far, all I've managed to organise is a grass-clippings dump over winter-sown potatoes, in the hope that the heat of decomposition would be just enough to protect them from frost. It seemed to work last year, but we had virtually no frost here (four days total) so hard to know for definite.

As for extracting the heat, what about running a small-diameter tube through the heap and into a restricted area of soil to create a limited hotter-than-average zone within the overall warm-ish greenhouse? I'm messing around with a cheap 12v pump (+solar panel & battery) and 8mm tube to solve an irrigation problem during my absences, which could surely be easily modified to create bottom-heat. I'd be thinking of a situation like my Lidl ginger being encouraged to sprout in a propagator - doesn't need much space at all at this stage, but really needs consistently warm soil.

iamtony

Yeah i was thinking of something like that alright.

As the infrastructure goes its all stuff I had lying around. We grew a good bit of lettuce and stuff indoors in hydroponic set ups in the past but the missus knocked that on the head when we got an aphid invasion.
I am thinking of getting a couple of the hydroponic units going and that's where I was thinking of using small tubes to heat the water in these units.
The greenhouse itself is old and has many broken panels which never really bothered me before as it kinda helped in the summer heat without putting that white wash stuff on the glass.
The lights I've got hanging down the tomato plants are sets I salvaged from IKEA stand up lights we were throwing out. They don't output a lot of lumens but better than nothing during the winter. The main thing is all the lights are very low power led's and everything I have when running is less than 100watts combined and they will only be on for about 5-6 hours in the evening.
Other ideas I'm playing with are making up something to sit on top of the bins to warm the soil.
Loads to play with anyway and the best thing so far has been able to play out there when it was dark outside and extending the day. Although the light is attracting crane flies in but hopefully the spiders will keep there numbers down :pac:

iamtony

So I got out and blocked up any broken panels with clear plastic and then I stared to get condensation on the inside of the glass as the moisture from the bin cant escape as easily.

Temperature of the compost rose to above 40° which is what i was aiming for with the size of my heap.

This is the one compost bin it's not even full, it is dropping though and I'm not sure if i should leave it alone and start another bin or fill that on to the brim. I could feel my legs and feet actually getting warm as the temperature dropped outside which is probably perfect for what I'm doing.

Sowed some seeds I had lying around and have them in the snake tank and its a steady 20° in there with the heat mat on.

Tomatoes are doing really well, the fruit is still ripening and new flowers everywhere.




And last but not least the flowers I took from the garden to try over winter are producing new flowers
post images

iamtony

Still climbing steadily.

iamtony

Temp peaked at 48° Celcuis yesterday morning. It was down to 40 degrees this morning and I turned it and it reduced to 30 as I spread out the heat. It will be interesting will it keep rising again or what's going to happen.

Tree

What temperature is the greenhouse?

iamtony

Tree wrote: »

What temperature is the greenhouse?

Early twenties with sun and about 10- 15 at night.

arctictree

Love this - what are the holes for on the sides of the bin? To let air in?

I had loaded up the trailer with used sheep bedding after lambing last year and the temp got to 50c inside. I'm thinking of filling an old wheelie bin this year and running a coiled hose pipe through it. Instant hot water...

iamtony

arctictree wrote: »

Love this - what are the holes for on the sides of the bin? To let air in?

I had loaded up the trailer with used sheep bedding after lambing last year and the temp got to 50c inside. I'm thinking of filling an old wheelie bin this year and running a coiled hose pipe through it. Instant hot water...

Yeah the aerobic bacteric need oxegen. If it doesn't get it it turns anarobic and starts to smell like piss apparently once it starts to cool you mix it up again and add extra oxegen. Temps are starting to drop in mine. It got back up to 40 degrees after turning yesterday but dropped to 38 today. I think i need to add more high nitrogen like tea bag and pond poo again. Obviously you'd have a good supply of manure.
Lots of videos on YouTube about it and extracting the heat for hot water.
The sheep bedding sound like it would work great. The finer you can chop it up the better.
I'm thinking now instead of running a coil through it I might create an alcove i can pull the bins in and out of and grow around them. It should keep them at a nice consistent temperature