Central heating with a furnace is an idea that is centuries old. One of the earliest forms of this idea was invented by the Romans and called a hypocaust. It was a form of under-floor heating using a fire in one corner of a basement with the exhaust vented through flues in the walls to chimneys. This form of heating could only be used in stone or brick homes. It was also very dangerous because of the possibility of fire and suffocation.

Furnaces generate heat by burning fuel, but early furnaces burned wood. In the seventeenth century, coal began to replace wood as a primary fuel. Coal was used until the early 1940s, when gas became the primary fuel. In the 1970s, electric furnaces started to replace gas furnaces because of the energy crisis. Today, the gas furnace is still the most popular form of home heating equipment.

Furnaces have been used in Minnesota for many decades and have been a common source of heating for homes and businesses in the state since at least the early 20th century. The first furnaces were typically coal-fired, but over time, they have evolved to use a variety of fuels, including natural gas, oil, and electricity.

Today, furnaces are a common and reliable source of heat in Minnesota. Many homes and businesses use them to provide warmth and comfort during the cold winter months. They are an important part of the state’s heating infrastructure and are an essential tool for maintaining a comfortable indoor environment during the winter.