energies Article Comparison of Emissions and Efficiency of Two Types of Burners When Burning Wood Pellets from Different Suppliers Grzegorz Pełka 1, Marta Jach-Nocon´ 2,3 , Marcin Paprocki 4,*, Artur Jachimowski 4 , Wojciech Lubon´ 1, Adam Nocon´ 3, Mateusz Wygoda 4 , Paweł ...