Fireplaces have undergone many metamorphoses throughout their history. One of these changes was due to Count Rumford, also known as Benjamin Thompson, a British citizen who spent time in the New World during the American Revolution. Rumford redesigned the traditional fireplace to make it a more efficient provider of heat and light.
Toward the end of the 1700s, Count Rumford realized that in order to improve a fireplace's output of light and heat, it must be designed differently. Creating the first of what would come to be called "Rumford fireplaces," Rumford built a fireplace that was designed to take advantage of the fact that head radiates outward. These Rumford fireplaces differ from traditional fireplaces in a variety of ways.
While traditional fireplaces were cube-shaped, designed for maximum space in which to build a fire, a Rumford fireplace is taller, shallower, and has sides which are splayed outward. In addition, Rumford fireplaces are designed to reduce the buildup of soot and improve the fire's efficiency. Count Rumford's design quickly caught on in both England, to which he returned, and the new United States of America.
Even Thomas Jefferson was convinced of the advantages of Rumford fireplaces, and had several at Monticello. Other old American and English fireplaces were "Rumfordized." This was done by raising the lintel's height and converting the firebox area by using additional bricks to make the area shallower and add the distinctive splayed sides.
Count Rumford had a very specific set of proportions in his fireplace design, and a fireplace must follow these measurements to be called a Rumford fireplace. For example, the width of the fireback, or back wall of the firebox, is equal to the depth of the firebox. In addition, the height of the fireplace's opening must be equal to exactly three times the depth of the firebox. The forward slope of the fireback must begin at 15 inches (38 cm) above the hearth floor. These are only examples; there are many more specifics for a fireplace to be a true Rumford fireplace.
For people who wish to have Rumford fireplaces today, there are several different options. Specific masons can be hired who have been trained in creating Rumford fireplaces. These masons have to take a course and pass an exam in order to be Rumford certified.
Other masons — or very adventurous homeowners — can build a Rumford fireplace from premade part or an entire prefabricated kit. Many prefabricated Rumford components are available, and some companies actually provide kits with fireplace parts that interlock. As long as the frame has been built, the stones and bricks can be laid to perfectly fit the proportions of Count Rumford.
Written by Bronwyn Harris