Lump wood
Heating by lump wood
We recommend heating by lump wood for outputs from 5 to 45kW. It is possible to combine this type of heating in fireplace stoves or interior boilers with other fuel like natural gas, heating oil, electrical energy, district heating etc.
At combination of fuels we can get also disproportionately more comfortable heating than wood itself. The supplementary heater (electric boiler, gas boiler) ensures tempering of flat e.g. during winter holiday etc.
Wood for heating uses more and more people. The main reasons are mainly increasing prices for gas and electric energy and last but not least also incresed interest in environmental protection.
Wood is considered to be the basic type of fuel and also renewable source of energy, which is used by mankind from ancient times. Wood is now experiencing a renaissance. For example, fireplace stoves or interior boilers VERNER are more desirable due to reducing costs for heating season. In combination with old way of heating e.g. gas or electric energy, it is possible to save up to 50% costs for heating season. With using of the interior boiler as a main source of heat, the saves per heating season can be even higher.
There is no wonder, that installation of interior boilers and lump wood boilers VERNER as a main source of heating is being a new lifestyle in these days, which is used mainly by young people in new houses.
And what are the main attributes for choosing of firewood?
Wood moisture
Freshly harvested wood in the forest have approx. 50% of moisture, low calorific value and high density. For heating in boilers or fireplace stoves, the recommended wood moisture is generally up to 20%. We can achieve this moisture, if we leave wood to dry at least 2 years on air under the roof. Compliance with the moisture of wood is very important especially for combustion in the pyrolytic boilers.
If we would not comply with this rule, there can be problems. Not only that wet wood has much more lower calorific value and also it burns worse, but also there is more soot and tar. There is also possibility, that moisture will condensate on the walls of the boiler and it can cause significant shortening of boiler lifetime.
Wood calorific value
Calorific value is quantity of heat, that we get by burning of 1 kg of wood. At moisture of 25%, the calorific value of wood is from 12 to 14 MJ/kg, these values are comparable with brown coal.
Wood hardness
Firewood is also distinguished according to hardness. In general, that wood from conifers is soft and wood from deciduous trees is hard. Hard wood is best for creating of stabel and prolonged heat, soft wood is conversely suitable for ignition and also for the case, that we want to heat the premises quickly.
