Hello I have read several articles about using compost heap for generating heat. Do these compost heaps have apecial c:n ratio? Are there any success stories about this subject? Thanks
Compost heaps that are used for heat extraction are not special in anyway, they are just built as hot compost heaps. The following links should help you with design and function. https://www.farmshow.com/view_articles.php?a_id=1444 https://www.farmshow.com/view_articles.php?a_id=1444 https://www.compostpower.org/ https://www.offgridworld.com/tag/using-compost-to-heat/
Thanks for the link. The cn ratio for compost should be in the range of 25-40. Does the ratio affect the heat generation? i.e which ratio gwnerates more heat?
The higher the nitrogen, the hotter the compost so if you build a heap that contains 30% carbon and 60% nitrogen you can reach temps of up to 165 f. A ratio of 25 c : 70 n can reach temps of over 200 degrees in a very short time. Example of Nitrogen heat factor: grass clippings put into a plastic bag and tied off will heat up to the ignition point in 2-3 days. If you build a heap and your thermometer shows it is not heating to the degree you desire, just add spent coffee grounds and moisten them, they contain around 40% nitrogen. You can also acidify soil or a heap by wetting with fresh brewed coffee.