Why is a pellet stove insert more efficient than a traditional fireplace?
If you are shopping around for a new pellet stove insert you may see EPA hang tags on newer models touting their tested efficiency. There are all kinds of ways a pellet stove or insert can be efficient but the efficiency these hang tags represent is the heat transfer efficiency, or simply; how much heat goes out the vent to the outdoors vs. how much heat stays inside the house.
Since the dawn of man, wood has been used as a fuel for heat and for cooking. Traditionally, homes were built around a stone or brick hearth located in the center of the home. During the winter these hearths were always kept burning which would result in the masonry radiating heat throughout the home. This type of heating was very inefficient by today’s standards and required enormous amounts of firewood.
In a little bit of American History, Benjamin Franklin made great advances in hearth design and construction, patented over 35 different heating designs and even has a fireplace created in his namesake, the “Franklin Fireplace” that is still made in some fashion or another even today.
Modern homes created in the 20th century through today may still have open fireplaces designed to burn wood but the heating efficiency in many ways is even worse than it may have been 300 years ago because modern fireplaces are not centrally located, are not sized for heating requirements and are not built for heating retention as they were long ago when the hearth was the only source of heat.
It’s not that uncommon for a fireplace built in a 1980’s home to register a 9-15% efficiency rating. This is a horrible number. Part of the problem as to do with fireplaces relegated to outside walls of the home and the other has to do with combustion airflow. Fire requires oxygen (air) to sustain combustion and fireplaces take this air from the air within the home which is often already heated.
As you burn a fire in the fireplace the heat escapes up the flue causing more air to be sucked into the firebox. If the only exposed masonry of the fireplace is the fireplace itself…well, there’s no chance for the masonry to actually radiate heat back into the home. As the heated air in the home is sucked out of the house up the flue, the cold air outside of the home is sucked into the house through cracks and gaps in the windows, doors and other poorly constructed areas causing the house to actually cool down.
Modern pellet stove inserts can boast efficiency ratings of 75% or more. And while we’re speaking of these listed efficiencies, if efficiency is really important to you, do your research because many manufacturers’ brochures list misleading efficiency numbers. Read this article.
Pellet stove inserts have the ability to convert a fireplace which is at best 15% efficient and get it upwards of 80% by restricting combustion air flow, optimizing combustion and circulating the room air through the appliances’ heat exchanger.
In fact, most of the homes that we install insert into are taking advantage of a fireplace in an end room, bonus room, family room scenario that was seldom used simply because it’s too difficult to heat during the winter and with the pellet stove installed, now the entire house is warm.
If you have a fireplace in your home, installing a pellet stove insert really makes sense because you’re updating a very inefficient system without taking up any more space.