One of the most debated topics in the heating community is whether coal burns hotter than wood. The answer can significantly influence decisions related to purchasing heating solutions, especially when it comes to stoves and furnaces. As homeowners and enthusiasts seek to understand the nuances of these fuels, comparing their heat outputs becomes essential. Let’s explore the science behind their burning properties and how they impact heat generation.
The Nature of Wood and Coal
To comprehend the heat differences, one must first understand the inherent properties of wood and coal. Wood is organic and primarily composed of cellulose, hemicellulose, and lignin. When burned, the wood undergoes pyrolysis, releasing volatile gasses that ignite and produce heat.
Coal, on the other hand, is a fossil fuel formed over thousands of years from decomposed plant matter. It is composed mainly of carbon and varying amounts of sulfur, hydrogen, oxygen, and nitrogen. Coal undergoes combustion in the presence of oxygen, releasing heat.
Calorific Value: A Key Determinant
The calorific value, or the amount of energy a fuel produces when burned, plays a crucial role in understanding whether coal burns hotter than wood. On average, coal tends to have a higher calorific value than wood. This means that pound for pound, coal can release more energy than wood, indicating that coal indeed burns hotter.
Combustion Efficiency and Burn Rate
While calorific value plays its part, the efficiency of combustion and the burn rate are equally pivotal. Wood tends to burn faster, especially when it’s well-seasoned. This rapid combustion releases energy swiftly, making spaces warm up quickly. Because roughly 80% of the energy in wood comes from volatile gases, it takes a specifically engineered stove to utilize these gases. The unburned gas is the smoke and creosote typical in wood-burning appliances. If your wood stove is smoking, your combustion efficiency is very low, only about 30% – 50%.
Coal stoves, in comparison, are known for a slower, more prolonged burn. Coal, especially anthracite coal, can maintain consistent temperatures over extended periods, resulting in a steady release of heat. Anthracite coal will burn completely, resulting in a clean, smoke-free exhaust. Unlike the complex engineering of the new wood stoves, coal stoves can remain simple and rugged. Anthracite is safer to burn because there is no chimney fire risk due to creosote build-up.
Airflow and Oxygen Supply
Airflow and oxygen supply influence the heat output. A well-regulated air supply in coal stoves is essential to maintain coal burning at optimal temperatures. Inadequate airflow can smother the coal, reducing the heat output. Wood, being less dense and requiring less oxygen for combustion, might not be as fussy about airflow. However, good ventilation always enhances the burning efficiency, regardless of the fuel.
Returning to the central question: does coal burn hotter than wood? The answer is yes. Coal burns at roughly 3,500F wood; if burned properly, it burns at 2,400F. In terms of calorific value, coal once again has the edge. Anthracite coal contains approximately 13,000 BTU/lb, and wood only contains 8,600 BTU/lb. If you are tired of loading your wood stove so often or need more heat, you might want to consider a Coal Stove.