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Wood Chips


  • Heating targets: two-storey detached house
  • Area: 240  m²
  • Fuel: wood chips
  • Heating system: central heating boiler (30 kW), stoker burner (40 kW),
  • Extra source of heat/thermal storage: baking ovenfireplace, tiled stove, Porin-Matti -oven, electric resistance
  • Other: emergency power generator

The main building (approx. 240 m²) in the Virkamäki farm heats up mostly with wood chips, as does the hot service water for the four-member family. Wood chips have been used for two years now. Before oil was used, and the consumption was about 4 000 litres a year. The former heating centre stood in a boiler room in the middle of the house. The new system has been built into a granary, from which the heat is transmitted through an underground pipe into the house.

The new boiler in the Virkamäki farm is an old, self-modified boiler (30 kW) from the 1980s. The stoker burner (40 kW) is manually fillable. The fuel silo (25 m³) has been built right next to the boiler room so that filling is as easy as possible and the amount of manual work low. Depending on the fuel, its quality and the weather conditions, the stoker is filled in every 1–8 days.

“I’ve burned everything sensible in the stoker. All fuels work well: peat, pellet and chips, and their different mixtures. I re-adjust the system when I chance the fuel, so that the efficiency is optimal. Not a single problem has occurred in our heating history, even though the equipment is old and used. We’ve used high-quality and dry chips,” tells the satisfied farmer.

“The heating costs are around 800 euros per year. The cost of oil heating would be approximately 4–5 -fold. Our kids don’t have to save hot water when they shower,” the happy farmer says.

“We spend about 50–60 cubics of wood chips yearly, depending on what the winter is like. We prepare wood chips twice a year. We buy the wood, and our neighbour comes with his tractor mounted chipper and does the chipping straight into the silo. If someone is hesitating because of the manual work a stoker demands, I can tell by experience that it doesn’t take many minutes at a time to fill the stoker. I save 5–6 euros every time I pop out to the boiler room, compared to if I was using oil heating”, counts the Virkamäki farm owner.

Halkolahti Dairy Farm

  • Heating targets: detached house, machine hall, cowshed storage, dairy
  • Area: approx. 360  m²
  • Fuel: wood chips
  • Heating system: central heating boiler (40 kW), burner (40 kW), unloader

Halkolahti dairy farm has used wood chips since 2002. The switch from firewood to wood chips was made when the house was extensively renovated and spaces were made more practical. One reason was to ease the heating process. The machinery hall heating that previously was electricity, is now also switched to wood chips.

This five-member family has a lot of space that needs heating: house (240 m²), hall space (70 m²) with four metres room height, cowshed storage (approx. 50 m²) and dairy. Also in the cowshed, which has 40 cows in milk and some young cattle, service water heats up with wood chips.

The annual consumption is approximately 180 m³. Part of the heat goes to a neighbour. Raw material for the chips is collected with own machines from own forests. A chipper contractor comes over once or twice a year and chips the wood straight into a concrete-floored silo (300 m³) next to the machinery hall. From this silo the fuel is transported with a tractor bucket to a week silo by the heating plant.

The boiler room and week silo are fabulously landscaped on a slope. The heating plant is unnoticeable, only smoke from the chimney reveals it. The silo has a hatch, through which the fuel is tipped into the silo (17 m³). The silo has an unloader. Even during bigger freezes, a full week silo is enough for three weeks. The boiler room has a stoker burner (40 kW) and a boiler (40 kW). A screw conveys the chips automatically from the silo to the burner.

“At first I did a little practicing with the machines. Its capacity was surely tested. I thought that the quality wouldn’t matter so much. But moist chips don’t burn,” tells the farmer, Esa, and continues: “also pebbles have gotten mixed with the chips sometimes, and one screw has snapped. I’ve been a little rough with the machine sometimes.”

"If the fuel has been good, the system has worked well. The only downside with this has been the unloader, which was poorly build and too weak for our needs. I reinforced it and now it works as it should.”

Also the woman farmer, Minna, is very satisfied with the present heating system. “We used to have to carry logs. It was much more physical work before,” says Minna and continues: “Now it’s easy and carefree. It’s nice that even if Esa has to be away from home sometimes, I can independently use the system.”

“I recommend wood chip heating for others too. I find it an excellent solution. When you’re buying a heating system, find the simplest one with the least small parts attached. Pay attention to the easiness of maintenance,” the farmer recommends, and guides that “you don’t need to dry the chips if it’s stored right and dry already.”

Editor’s comment: If oil was used in Halkolahti, the consumption would be 14 500 litres of fuel oil per year. The price of this would be 16 600 euros. With the silvicultural influence counted in, the price is even higher. Halkolahti farm saves loads of money with wood chip heating

Beef Cattle Farm Marjorinne

  • Heating targets: two-storey detached house, granary accommodation buildings, repair facilities
  • Area: 370  m²
  • Fuel: wood chips
  • Heating system: central heating boiler (60 kW), mechanical grate incinerator (80 kW), spring agitator.
  • Extra source of heat/thermal storage: fireplace, electric resistance
  • Other: emergency power generator

Marjorinne has been heated up with wood since 1987, when it was a dairy farm. Then it was important to get hot washing water in the cowshed. Today, when there is beef cattleinstead of dairy cattle, wood chips are used to heat up the repair facilities, the main building and the granary accommodation buildings, the total area being approximately 370 m. Also the five-member family requires its share of the heating.

Prior to building the new system, consumption was 100 m³ of wood chips, but now it has dropped to 70 m³. The new system includes a central heating boiler (60 kW), a mechanical grate incinerator (80 kW), and a spring agitator. The boiler also has an electric resistance. In case of power cuts, there is an emergency power generator. Wood comes from own forests, and the felled and lopped trees are chipped with own chipper. The wood is chipped straight into a silo (30 m³) without intermediate storing.

“I’m completely satisfied with wood chips, and I recommend them to others as well”, says the farmer, Ville, and continues with a smile on his face: “Before we had some problems with the old equipment. The stoker’s screw was too small and there was not enough power. The efficiency was poor. The stoker with its small screw was too picky with sticks and the quality of the chips”.

“I recommend to get a stoker that is slightly bigger than what is the estimated need. For us, the 20 kW stoker was too small. But dad sure was a wise man when he started to use chips,” Ville smiles. “When we were little our father used to make us a skating ice with water that was first heated up with wood chips. He didn’t mind the great consumption of the fuel when it was practically free, even though it was the time of energy crisis. Otherwise dad was an economically precise farmer”.

“In 2003 all equipment was renewed and the estimated cost was 23 000 euros. The share of our own work contribution was remarkable. It is nice to have a spring agitator, you don’t really have to go to the boiler room. We might have coped with a smaller system of 40 kW boiler, but I wanted to have a little reserve. It’s been working well. Not a single problem has yet occurred. The payback is not a problem either, when energy is so cheap. The system has already paid for itself, many times. The previous equipment lasted for 30 years, even though it was smaller in relation to consumption and use”, Ville smiles.

“It works beautifully in the summer as well, but I’ve heated the service water with electricity in the 60 litre hot-water tank. It has been enough, since in the summer there is nothing else that needs heating. That saves me from sweeping, which I have to do in every couple of weeks in the winter,” smiles Ville.    


  • Heating targets: detached house, workshop facilities
  • Area: approx. 300  m²
  • Fuel: wood chips, oat
  • Heating system: central heating boiler (40 kW), mechanical grate incinerator (40 kW), drag conveyor
  • Extra source of heat/thermal storage: fireplace, electric resistance
  • Other: GSM-alarm system

Farm Jokihaara has always been heated up with wood. Formerly with firewood, today with wood chips. When the old cowshed was transformed into workshop facilities in 2010, a wood chip-fuelled central heating system was installed at the same time. Both the house ( approx. 180 m²) and the workshop facilities (116 m²) need heating. Room height in the workshop facilities is almost four metres.

The new heating system, the centre and the fuel storage, is elegantly integrated into old grain silos. The system consists of boiler (40 kW), mechanical grate incinerator (40 kW) and a drag conveyor. The system also has a GSM-alarm system. In case of emergency, the owner, Asko, receives a text message in his mobile phone. According to Asko, the alarm system is a very useful accessory, making the use of the heater carefree. Ash is removed from the boiler with a cyclone ash vacuum. The total cost estimate of the system is around 20 000 euros, installation costs excluded.

“There’s plenty of heat, and everything has worked faultlessly. We have burned both wood chips and oat. The mechanical grate incinerator is an absolute necessity in the system. I recommend it to everyone who is buying this kind of a system,” says Asko and continues: “It saves you from any extra work at the boiler room. We have no trouble with ash stoning. Although the quality of the wood chips has to be good. I try not to use branch chips, only chips made of trunks, because sticks can cause failure alarms in the feeding system. But it’s simple to fix it: just take the stick off of the light sensor”.

“The system is working so well, that sweeping tends be done too rarely. You don’t have to watch this system, you can instead do your other work,” tells the satisfied Asko.

“We get the wood chips according to possibilities and circumstances. A wood chip contractor comes here and prepares chips of our own trees. And if we don’t currently have wood of our own, we can buy raw material from our neighbour. I can warmly recommend this heating form to others as well. Especially a system with which you can burn almost anything”, guides Asko.


  • Heating targets: detached house, garage
  • Area: approx. 200  m²
  • Fuel: wood chips
  • Heating system: central heating boiler (35 kW), stoker burner (40 kW), hot-water tank (2 000 l)
  • Other: vacuum-pipe solar collectors

In Kuusiranta, the main building and garage are heated up with wood chips, and the total area to be heated is approximately 200 m². The heating system consists of a stoker burner (40 kW), which is connected to an old, self-modified downdraft wood boiler (35 kW). There is also a 2000 litre hot-water tank in the boiler room.

Before chips, firewood was used in Kuusiranta. Logs were switched to chips because burning chips is automated further and requires less work. “We have practically an eternal fire here, and plenty of hot-service water available. With one stoker-load of chips we live comfortably for two days even if it’s minus ten degrees outside,” tells the house owner Seppo.

The annual consumption is 30 loose cubic metres (m³ᶩ ͮ). Fuel is rationed manually into the stoker. Chips are made with own chipper of own trunks.

Woods chips have been used in Kuusiranta for ten years now. A novelty is a vacuum-pipe solar collector system, which is planned to be taken into use in the spring 2013. The solar energy collected should heat up service water from May till August, when heating is otherwise not needed.

“The system has worked very well. We’ve had no problems at all. Formerly we had problems with backburn protection. Those we don’t have any more. The protection was made of bees wax, and it seeped water into the stoker. If you have old equipment, change the protection to a new one. It should help,” guides Seppo.

“If you’re planning to switch to wood chips, plan the logistics well. This way heating is nice and easy. We use a tractor trailer as a fuel storage. It’s not the handiest solution, but it works. Otherwise this is an excellent heating option, carefree and, especially, affordable,” Seppo says.

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