Why is a Fireplace Xtrordinair® wood fireplace more efficient, producing more heat than the open fireplace I grew up with?

Our zero clearance wood fireplaces are clean-burning EPA certified home heaters. They are all sealed appliances that pull all of their combustion air from outside, so you are not using your heated air from inside for combustion. And in many cases, installing a zero clearance wood fireplace is half the cost of installing an open masonry fireplace.