“There are many advantages in heating with chips, especially if you have your own forest
The remark comes from Svend Erik Sund, who utilizes wood waste from both the forest and from hedgerows to produce wood-chips. “You keep the forest nice and clean and on top of this, you have access to cheap heating-material”.
It needs some work to make the wood-chips, but other than that it doesn´t cost him anything.
Since the mid nineties Svend Erik Sund has used wood-chips as his main heating source. He owns a 320 m2 big country house with 11 hectare spruce forest situated in the middle of Jutland in Denmark.
He utilizes between 0,2 and 0,8 m3 chips per day and night depending on whether it is summer or winter. This is equivalent to approximately 200 m3 per year. One m3 wood-chips is equivalent to around 60 liters oil, which is the same as 12.000 liter oil per year.
Svend Erik Sund uses a wood chipper model TP 230 from the Danish manufacturer Linddana A/S to cut his trees to chips. The model is equipped with a stress control system, which means that it regulates the in-feed and it also produces uniform chips which is perfect for heating purposes.
10-15 m3 wood chips
The advantage of chipping one´s own wood is, that the high quality wood can be sold as timber and the rest – branches and tops – can be used for heating purposes.
The needles from the spruces however, must preferably be kept in the forest. The needles contain a big amount of manure which gives the soil the necessary nourishment. It is therefore important to leave the trees to dry until the needles fall off before the wood is chipped.
Svend Erik Sund always cut down the wood while the water is still in the roots, which is from November to February. He then leaves the wood until the following year, so that the water content comes down to 25%. The water content is an important issue if the wood is made into chips. If the water content is too high the risk of producing mould or the chips begins to ferment.
A simple, but a very correct way of measuring the water content in the tree is by taking one kilo chips and put it in a 100 ۫ hot oven for 2-3 hours. If the chips now weighs 750 gr. does it mean that the water content is 25%, as 250 gr. is evaporated.
Svend Erik Sund has installed a TwinHeat heating system for chips and pellets and he uses both heating materials. The wood chips are used on a daily basis and pellets are used during holidays, as they last longer. Wood chips take up more room than pellets and for this Svend Erik Sund has a separate silo which can store one weeks consumption of chips.
