Sheldons was founded in 1896 in Galt, Ontario, with the object of incorporation being the manufacture of air handling equipment. Sheldons was the first company incorporated in Canada for this purpose. W.D. Sheldon and S.R. Sheldon were involved in the early origins of the factory at a time when it was making forges for blacksmith shops and heating boilers for homes. In due course, reflecting the industrial demands of the time, Sheldons produced a line of ventilating and forced draft fans, many of cast iron. The factory also supplied and installed highly involved and ingenious manufacturing and heating equipment for many Canadian pulp mills. Sheldons Engineering has a dealer network accross Canada and the USA.
The factory at that time was located in the present downtown location of the larger plant. In 1911 Sheldons built a foundry and later developed a series of products for military applications during the First World War. In 1916 an additional manufacturing area was constructed making Sheldons the largest manufacturer of fans and air handling equipment in Canada. During the Second World War, Sheldons was awarded a contract to produce forced draft fans for the boilers of all 5,000 and 10,000 ton liberty ships, and every mine sweeper, corvette, trawler and frigate built for the Royal Canadian Navy was equipped with Sheldons fans and steam engines furnished by Sheldons to drive the fans. In 1947 the foundry was converted into a modern fan fabricating plant and this plant was continually improved upon and expanded through the 1950's.
In 1956 a modern fan test facility was built for air and sound testing and with further improvements and additions. In 1966 a new plant was built in the Northern Industrial Park in Galt and Sheldons Head Office was moved there. W.D. Sheldon Jr. died on March 7, 1973. Currently, Sheldons Engineering Inc., purchased from Strong Co. in 1996, operates from its Mississauga plant. Sheldons now focuses its efforts on building commercial and industrial blowers.