Does Compost Heat Really Work?

Does Compost Heat Really Work? ENERGY Miscellaneous Researcher Sam Gorton is confident composting for heat can pay off big The University of Vermont graduate student has been evaluating compost heat systems and currently has two systems going in Vermont “Both are insulated with hay bales and set up to heat greenhouses ” says Gorton “Both are outfitted to measure water temperature and compost temperature at different depths Based on my research a realistic recovery estimate is 1 000 btu’s per hour per ton of active compost for up to 6 months ” Gorton starts by laying down a foundation of wood chips for the compost mound He then coils rigid plastic water pipe under 6 to 18-in thick layers of compost Once the pile is completed a mixture of glycol/water or straight water is pumped through the pipes collecting heat from the compost “The heated water can be pumped to an in-floor radiant heat system fluid-to-air radiator panel or heat exchange system ” says Gorton A proper compost mix is key to maximum heat production advises Gorton This includes the carbon-to-nitrogen ratio moisture content relative biodegradability porosity needed for air flow and the physical shape “If you’re interested in composting the heat can be a free byproduct and potentially displace fossil fuels ” says Gorton “Before it can be used the compost will likely have to be turned again and stabilized or cured after heat recovery is finished Unfinished compost can burn crops ” Gorton is coordinating his research efforts with Highfields Center for Composting a Vermont non-profit “They do compost consulting and offer free information on their website ” he says “We are trying to create a network of folks working on the concept ” He also recommends visiting the website for Agrilab Technologies www agrilabtech com Agrilab has installed an on-farm air-based heat recovery system for a large dairy Other good sources include Cornell University’s composting website and the On-Farm Composting Handbook from the Northeast Regional Agricultural Engineering Service Contact: FARM SHOW Followup Sam Gorton c/o R3 Fusion Inc 405 Jordan Rd Troy N Y 12180 ph 518 496-4252; gortonsm@gmail com or Highfields Center for Composting Attn: James McSweeney P O Box 503 Hardwick Vt 05843 ph 802 472-5138 ext 201; james@highfieldscomposting org; www highfieldscomposting org

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