燃やす
biomass
climate protection
co2
co2 neutral
combustion
consumption
ecosystem
embers
energy
energy forms
environmental protection
fire
firewood
flame
form of energy
fuel
fuels
heat
heat source
heating
heating costs
heating demand
heating material
hot
indoor climate
material cycle
open fireplace
radiant heat
raw material
renewable
renewable energy
resource
resources
sustainability
sustainable
temperature
warm
warm up
waste wood
wood
wood heating