It does not produce more heat, it just radiates the heat back into the room. The heat is not just in the flame and going up the flue like wood or fire logs. The heat is radiated off the glass and into the room making your fireplace more efficient. It takes very little flame to heat the glass and then the glass radiates the heat back into the room. Your Family and Friends will notice a considerable difference in heat output from your Fireplace and Fire Pit.