David Lennox was born in Detroit, Michigan on April 15, 1855. He was the son of an expert railroad mechanic, and it was clear early on that Lennox had inherited his father's mechanical ability. He quickly became interested in tools and machinery and discovering how things worked.
Shortly before the Civil War, the Lennox family moved to Aurora, Illinois where they established a machine shop. As the Civil War began to heat up, Lennox's father decided it would be right for him to enlist in the war effort, and he did so for a period of three years. He left home once, returned, and then left again. Tragically, that was the last time the family saw him. Lennox's mother moved the family to Chicago where she ran a grocery store. There, Lennox worked in several machine shops, continuing to hone his mechanical and design skills.
In 1881, Lennox set off for Marshalltown, Iowa, looking for work. He set up a machine shop and was happy to take on the project of creating a staple-making machine for a local businessman. He designed a machine that increased production while lowering costs. It was an instant success. The reputation of the Lennox Machine Shop started to grow beyond Marshalltown city limits. Lennox began planning his own projects, including improving the designs of tools such as trowels and shears.
One day, a couple, Ernest Bryant and Ezra Smith from nearby Oskaloosa, Iowa, dropped by Lennox's shop to show him their plans for a new kind of furnace. The furnaces used to heat homes at that time were made of cast iron, which warped and cracked after extended use and caused smoke and coal gases to seep into houses. Bryant and Smith's design was more durable, as they used riveted steel for the heating surface and iron castings for the grates, fronts, and other parts. They asked Lennox if he could make the iron castings for their furnaces. He agreed.
Later, however, Bryant and Smith found themselves unable to pay Lennox for his work. They couldn't find financial backers for the business they had wanted to establish. So, Lennox took over the patents that they had on their designs and started reworking and improving on them. He began building the first Lennox furnaces. The designs he came up with caught on very quickly.
By 1904, however, Lennox was tired of the furnace business, so he sold the company for $54,789 to newspaper publisher D.W. Norris. During the Lennox Furnace Company's first year of business under new ownership, 600 new furnaces were sold.
Today, the company is a multinational, public corporation called Lennox Industries and is still controlled by descendants of the Norris family. A "David Lennox" persona has been featured in Lennox advertising since the 1970s. Lennox Industries is no longer limited to furnaces only. Today, the company makes air conditioning, heating, and fireplace systems for residential and commercial use and develops and sells commercial refrigeration equipment and heat transfer surfaces. Company brands include Lennox, Armstrong Air, and Ducane.