Although the company as we know it today was established in 1975, the company's roots go back well beyond that date.

It all began back in the early 1950s. There were three plumbing and heating warehouses all owned by the same man, Harry Yelton. One was located in Granite City, Illinois and was called Metro East Supply another was located in Belleville, Illinois and was called Belleville Supply and the third was located in St. Louis, Missouri and was called Mid Valley Supply.

While the business was mostly plumbing, the also carried a line of heating and air conditioning with the brand name of Inland Heating & Air Conditioning. It was a brand privately labeled by Mr. Yelton just for his companies.

In time, the branch in Granite City closed and the one in Belleville was sold off. By this time, Harry had died and left the remaining store to his son, Harry Yelton, jr. who changed the company name to Yelton Supply.

During the same time, a man named Carl Langendorf was the regional sales manager for the Janitrol Heating & Air Conditioning Company that was located in Columbus, Ohio. His office was located in St. Louis, Missouri. One of their biggest customers in the area was Henson-Robinson in Springfield, Illinois. In fact he sold so much equipment to them, Carl convinced Janitrol to open a branch office and warehouse in St. Louis to better service the area. It was located at 1720 Macklind Avenue, just down the street from the old Highlands Park. When Carl opened the warehouse in 1958, he hired Ken Arnsmeyer, Sr. who at the time was running a warehouse in East St. Louis for a warehousing company named Columbia Terminals, formerly McMahon Transfer.

In 1966, Janitrol decided to close the warehouse in St. Louis. Carl went to Columbus to become the national sales manager for Janitrol and Ken went to work for Yelton Supply who then became the distributor for the Janitrol brand of heating and air conditioning. The office and warehouse were located at 3740 Sullivan Avenue. It was adjacent to the old Sportsman Park and originally had served as a parking garage for the stadium.

In 1968, Carl returned to St. Louis and he and two of his business associates, Ed Gaus and Len Scott of the Gaus-Scott company purchased the Yelton Supply Company from Jackie Yelton, Harry's widow. They renamed the company to Langendorf Supply (Division of Gaus-Scott) and in 1972 moved to Earth City.

They rented office and warehouse in one of the few buildings located in Earth City at the time. The building was owned by Systemaire, Inc. They supplied a lot of the rooftop equipment to some of the first buildings in Earth City because of their relationship with Systemaire who was the installing contractor. A. C. Sytems also leased space in the same building and was located between Langendorf Supply and Systemaire.

At about this time Dave Fahrenhorst was hired as a salesperson. Langendorf represented Janitrol equipment as well as Arkla gas airconditioning, a gas fired residential absorption chiller. Leads were provided to Langendorf through Laclede Gas Company who would finance the purchase of the unit on a person's gas bill. They received discounted gas rates in the summer.

After multiple bankruptcies, the Janitrol line folded. Arkla purchased the rights to produce their gas furnace to couple with the air conditioning. They developed the first Recouperative gas furnace, a high efficient condensing furnace. It was the first of its kind. Many other manufacturers quickly followed.

In 1975, the company was sold to Ken Arnsmeyer, Sr., Dave Fahrenhorst and Ken Arnsmeyer, Jr. As the business was still small, Ken, Jr. continued to work as an field Engineer at the Union Electric Company and remained a silent partner until 1977 when he joined the company. The company continued to operate as a residential wholesale distributor until 1978 when they were awarded the Titus line of grilles, registers and diffusers. The company started moving into the commercial Plan & Specification market. Shortly thereafter, Loren Cook followed and the shift to commercial was almost complete. They acquired Arrow Louvers and National Controlled Air dampers to complete the commercial air distribution package. Some 8 years later, Ruskin joined the mix and things really took shape.

Under the leadership and sales of Ken, Sr., Dave and Ken, Jr., Langendorf Supply became a consistent top 15 performer for Titus, Ruskin, and Loren Cook.

In 1981 Ken Arnsmeyer, Sr. retired from Langendorf Supply but it didn't take him long to become bored. He purchased a truck and began delivering for the company. He called his company Florissant Fast Freight. He afforded the company the ability to offer delivery anywhere in the city at anytime of the day. This he did until in 1991 when his eye sight became to bad for him to drive and he reluctantly gave it up.

In his absence, the two remaining partners shared the management duties with Dave taking responsibility for the sales area and Ken taking responsibility for the warehouse and accounting areas.

Dave's dad, Lefty, we called him had also retired from his regular job. He would come in regularly to do things such as install plenums on vav boxes, mount controls of vav boxes, and install pattern controllers in slot diffusers so they would not need to be installed in the field. He also did a variety of other jobs for the company and was always an asset to have around.

Both of these men contributed greatly to the company success and they were greatly missed when they had to call it quits.

Langendorf continued to grow and gain market share within their territories. They were recipients of numerous awards for market share, making quota and total volume.

In 2002, with the encouragement of Titus, Dave and Ken, Jr. decided to open an office in Peoria, Illinois. The existing Titus Rep had consistently been losing market share. The office didn’t take long to succeed and brought rewards quickly. Within a short period of time, Loren Cook, Ruskin, and Lindab followed the Titus lead and awarded the territory to Langendorf. They were off and running again.

In June 2003, Krista Arnsmeyer joined us which marks the third generation family member to be employed by Langendorf Supply.

In 2005, Dave decided to retire. Having led Langendorf Supply Company in sales since the early 1980's, replacing Dave was not an easy task. Although Langendorf had other capable people, few in the industry garner the respect that Dave had achieved throughout his career at Langendorf Supply.

Also that year, a similar opportunity occurred in Indianapolis that had occurred in Peoria in 2002. It was Lindab this time. Lindab was quickly becoming one of Langendorf's premier lines. Noticing their success in St. Louis, Lindab asked Langendorf to open an office in Indy which they quickly did. In fact, they opened an office in Fort Wayne as well. Success though was not as easy to find as it had been in Peoria. They found themselves at the grass roots trying to establish identity in an entirely new market unlike they had in Peoria.

Today Langendorf Supply Company continues to operate with one goal in mind, delivering superior customer service to all of our customers without compromising the highest ethical and moral standards.