Using compost heat for perennial production
The goal of our project is to heat our greenhouses with heat generated from our compost pile. We would like to generate enough heat to maintain a 45 F temperature in the greenhouse. The greenhouse to be used in this project will support perennial production. It is our desire to understand if compost heat is a viable heating alternative to fuel oil. If so, this would reduce heating costs for growers and allow similar farm businesses to be more profitable.
Kelly McAdam, UNH Cooperative Extension Field Specialist for Belknap County, continues to be our technical advisor. She has been outstanding, and we never would have got off the ground without her. She brought in experts to assist us with the engineering and monitoring aspects of this project. Stan Weeks, an agriculture engineer, and John Porter, UNH Cooperative Extension Dairy Specialist, Emeritus, have both been to the farm several times to offer advice and answer questions as we design this project and plan for the necessary parts of the heating apparatus. Brian Krug, UNH Cooperative Extension Greenhouse Specialist has also offered expertise on methods for monitoring the temperatures of both the compost pile and the greenhouse with a system that will provide readings wirelessly to our laptop computer.
The first stage of this project was to build a heating coil to be enclosed in a cage inside of the compost pile. To do this, we have hired a fabricator. At this stage of the project the heating coil almost complete. The next step is to connect temperature-sensing probes and a recorder to the coil apparatus, which will then connect to a laptop computer and the heating system in the greenhouse. The probes, wires, and recorder were purchased in September of 2014 and are ready to install. The laptop computer and software needed to record temperatures from the recorder has not yet been purchased or installed.
Insulated holding tanks have been purchased, and will be placed inside the greenhouse to capture radiant heat in the daytime which will then be pumped back into the compost pile when the thermostat calls for heat. Heat tubes will be placed in the greenhouse floor to keep the root zone at the optimum temperature.
The remaining timeline is as follows:
Complete heating coil apparatus and place in compost pile—March 2015
Greenhouse heating system set up complete—July 2015
Begin system and test—September 2015
Perennial production begins—November 2015
Grower Meeting—November 2015
Impacts and Contributions/Outcomes
UNH Cooperative Extension
Spaulding Hall, 38 Academic Way
Durham, NH 03824-2617
Office Phone: 6038620155
Field Specialist, Food & Agriculture
UNH Cooperative Extension
635 Main St. Third Flr. Suite One
Laconia, NH 03246
Office Phone: 6035275475