Greenhouse heated by compost - amateur experiment

I have had a compost pile on the farm or in my backyard since I was old enough to know better.  My grandfather, an avid gardener and phenomenal green thumb, had a compost pile in the corner of the garden where we would deposit our cat litter, onion trimmings, banana peels and more.  Every spring he would turn the pile over and arduously spread it across his garden and then turn it in - all by hand - with no mechanical intervention.  He did this in our backyard in Greenwich, Connecticut, of all places.  It never smelled, it was always the warmest spot in the garden and I can't ever remember it having snow on it.  He also had a greenhouse.  It was heated with propane, to my grandmother's dismay.  He spent hours out there every day in his retirement.  His goal - to have tomatoes on the 4th of July.  I think he missed one year by three days between my 8th birthday and when he passed just after my 22nd.

Next to the garden, I have a huge compost pile.  It accepts almost all of the shavings and manure from the chicken coop, the remnants of the garden after it is cleaned out in the fall and any other large deposits of vegetation, grass, leaves and weeds that are collected here on the farm.  This year, I also started a compost pile in the greenhouse.  I had read one of the many articles on free heat for a greenhouse.  There are some pretty impressive systems out there where you run pipes through and around your pile and then run water through those pipes to heat the greenhouse.  My system is much more low tech.  In the greenhouse, I built a compost pile (meaning I took a corner of the greenhouse and started piling up organic material).  Recently, I renewed my efforts, to collect coffee grounds and food stuffs unfit for the chickens and pigs so that they be added to my pile in the greenhouse.

I can report some moderate success.  The outside temperature today did not exceed 32 degrees and it was 45 degrees inside the greenhouse.  The true test this week will be to see if the pile can keep the inside temperature over 32 degrees as the outside temperatures are forecast to remain in the low teens for highs and close to zero for overnight lows.  If I can maintain a temperature close to freezing, then it will be time to start some early spring crops like spinach, greens and radishes for personal consumption.

Later this year I hope to add some radiational heat retention with bricks found on craigslist for a new floor and perhaps a water barrel painted black.  Always a work in progress.