Heating a house from compost: how the bioreactor works, the principle of the system
The biomeiler or compost water heater was invented by the Frenchman Jean Payne over 60 years ago. Now his brainchild is used by many farmers and country house owners in Europe. On what principles does this heating system work and how to equip it - read on.
Why does the compost get hot?
The heat generated by the compost is a side effect of microbial activity. Heating the biomass means they eat up the organic matter and convert it into finished compost. That is, a biological reaction is obtained that releases heat - hence the most appropriate name - bioreactor.
Three types of microbes work in the compost heap: psychrophiles, mesophilic and thermophilic bacteria. Thermophilic bacteria are responsible for heating the biomass to 60–65 ° C. The reaction with maintaining this temperature inside the heap can last from 3 to 18 months.
How to build a biomaler?
The system is very simple. It consists of a compost heap and a plastic pipe with a constantly circulating coolant, which, after heating, enters the heating radiators.
Arrangement of a biomeiler is carried out as follows:
- First, the frame is erected. It is usually made of mesh reinforcement, but it can also be made of wood. The frame's job is to hold the compost heap. In addition, it must have thermal insulation properties so that the resulting heat does not escape to the outside. To do this, it is laid with agrotechnical cloth and insulated with straw or mineral wool. The main condition for insulating a structure is to leave access to oxygen, which is necessary for the reaction to proceed. If the compost pit will be outdoors, it must be protected from precipitation. The best way is to build a canopy.
- A pipe or hose is laid inside the frame. In most cases, the pipes are placed at the bottom of the compost heap at a distance of 30–40 cm from the bottom, and then they are lifted in a spiral along the inner mesh frame to the top of the structure. The length of the pipe is not regulated, but the longer it is, the faster the coolant will warm up. For heating one house with an average area of 60 sq. meters, it is recommended to lay a pipe of at least 20 mm in diameter and at least 80 meters in length. Moreover, effective heating of such a house requires 7-10 cubic meters of compost.
- The pipes laid inside the compost heap are connected to the heating system of the house. Further, everything is like in classic heating - the coolant heats up, passing through the compost heap, and is fed into the house with the help of an electric pump. Pipes that deliver the coolant to the heated building must be carefully insulated. With the correct design of the system, the temperature of the radiators in the room will average 45 ° C. This is enough to maintain a comfortable temperature in the house.
What kind of compost is needed for a biomaler?
In order for the reaction to last as long as possible, it is better to use crushed branches, wood chips, sawdust, fresh grass, hay, and manure for compost. When using manure, take into account the specific odor that the compost heap will emit.
The biomaterial is laid as follows:
- first, a layer of vermicompost 5–7 cm is laid on the bottom, which will give the necessary composition of bacteria;
- then, up to half of the volume, the rest of the compost material is poured and all this is poured abundantly with water;
- then another layer of vermicompost is laid, the pit is filled to the top and again spilled with water.
The reaction with the release of heat begins approximately 7-10 days after laying.