pellet stove fire flames heat heater source alternative burning burns burn comforting comfort conservation conserves conserve conserving electric energies energy fireplaces fireplace flame flicker eco friendly glowing glows glow green heating home hopper hot household intense pellets recycled recycle recycling renewable up warmth warm wooden brilliant close color colour cast clean comfortable contained detail environmental environment horizontal face firebox forced air glass ignited inexpensive iron metal orange pot powers power radiance radiant window winters wintertime winter