I am also interested in the use of compost-generated heat in the coop. Chickens will tolerate a very low temperature in their coop but I am primarily interested in keeping the nest area warm enough that eggs won't freeze while I am away all day during our Maine winters.

I'm building a technologically simple system of circulating a fluid through coiled tubing in the compost pile and then to a short section of baseboard heat under the nest boxes. The compost pile will be outside the coop and will be much larger than the one you envision.

Inside, I would be very concerned with the amount of ammonia that you might be introducing into the hen house through active composting of their wastes within the coop. Health warnings for ammonia levels are human related. Animals are much more susceptable to the effects of ammonia then are humans and though you might not notice the odor, or get used to it rather quickly, animals can begin to show adverse reactions after a couple of weeks of exposure. Rabbits are particularly sensitive to levels undetectable by the human nose. Chickens will suffer with weeks at levels half that which humans can easliy acclimatize themselves to.

A study looked at the effects of ammonia at varying levels on chickens and other animals. It found chickens to be at risk for pulmonary edema, congestion, and hemorrhage depending on the levels of ammonia exposure and duration. (All levels were within the safe zone for human exposure.) Chickens exposed to high levels (but still within levels safe for humans) were also found to be increasingly susceptible to Newcastles Disease.

I'd suggest you try to find a way of filtering the ammonia emmissions from your compost while still retaining the heat.

(I included a link to a study since there will invariable be someone who will tell you that their coop stinks to high heaven and their chickens are fine.)

Wayne

Here is a link that might be useful: For those who like research citations....

Thanks for the link & I'm interested to know how your project turns out. Composting just outside the coop would work for me, too, and I'd have materials to make a big compost pile (cow and horse manure). What are you using to circulate the water? A small pump of some type?

I use the deep litter method, and for some reason, my coop doesn't stink. It is dusty, though.

Need to shovel the coop tomorrow and start a new outdoor compost pile. Yuck. I hope the droppings board makes it an easier task in the future.

I saw plans for a chicken coop once, that had a hinged panel outside, that you could raise, opened just under the perches, giving easy access to that area from outside.. I thought it would be handy, but, unfortunatly, my hens live in Fort Knox.

MH,

I'm first going to try a closed loop relying on convection to move a glycol solution from the hot compost to the cool henhouse. The short section of radiator under the nest boxes will be at the highest part of the loop. As heat is extracted, the cooled water will begin the downward leg of the loop, back to the compost, where it will be reheated.

I'm trying to avoid a pump for two reasons. First is that I don't want the added expense and complication I can possibly avoid it. But more importantly, I don't want to force too much heat out of the compost pile as lowering the temps drastically seems to somehow "stall" the pile, as experiments at Mother Earth News many years ago showed. A circulation faster than the natural convection flow seems like it may pump more heat into the coop than I need. I only want to keep the eggs from freezing. The birds will largely be on their own for warmth. (Keeping chickens artifically warm all winter can have serious consequences should the power fail and they are left in temps to which they haven't been acclimatized.)

I was thinking about your idea of in-coop composting and perhaps an enclosed metal cylinder such as a steel drum that you could run a simple fresh air intake hose and vent to the outdoors might work. Using a series of 55 gallon drum composters was an idea I was considering for use in a small greenouse where ammonia can be very detrimental to plants.

Wayne

When I had chickens I used sawdust or fine wood shavings on the floor and straw or old dry hay in the nesting boxes. I kept the nesting boxes clean (cause I like clean eggs!) but just kept adding more sawdust to the floor area. When it got deep I shoveled it all out to a pile, limed the floor, and added fresh sawdust. The coop always smelled nice and like wood not like chicken manure. It was also warm even in our cold winters as I cleaned it in the fall and left it til spring only adding more sawdust.

If you have dust from the chicken manure that's a very unsanitary condition for the chickens as well as for any humans who have to go in the coop.

I think you'd have to add a lot of shredded paper to chicken manure cause it's pretty "hot", that is nitrogenous.

I've heard good things about deep bedding. I'm guessing that all the sawdust does a pretty good job of mitigating the ammonia; because there seem to be a lot of people that practice this with great success. My mom is doing it and the henhouse never smell of pooh/ammonia unless it's due for another layer of sawdust.

When we had chickens I used dry leaves as the litter in the henhouse and never had a problem with ammonia production and the girls had a real good time mixing their manure into the leaf litter. Because this was a quite dry mixture when clean out time came dust could be a problem so you would need to wear a good dust mask. Poultry manure, potentially, can contain the pathogen that causes Histoplasmosis, a respiratory condition that contributes to Asthma and COPD.
If you actually did try to compost this in the chicken coop, I did not, because of the moisture levels necessary for composting you might create problems you do not want, ie the Ammonia which indicates a loss of Nitrogen during composting.