Ключевые слова: alternative, bio, biofuel, biological, biomass, brown, burn, closeup, compressed, eco, ecological, ecology, economy, energy, fire, fireplace, firewood, fuel, head, heap, heat, heater, industry, mass, material, nature, pellet, pine, power, radiator, recycling, renewable, roll, stove, temperature, thermal, thermostat, thermostatic, timber, valve, warm, winter, wood, wooden,