The history begins in a cold Vermont winter in 1975 whith the inventor Eric Darnell. He improvised housing, despite its brand new wood-fired stove would not get sufficiently warm.

At that time, Darnell earned a part of his income through the installation of specially bent steel tubes in open fires in that way, that their heating capacity – without electric blowers – was noticeably increased. For this, he made use of the fact that hot air rises (convection effect). From his knowledge gained here and the analysis of the weakness of his radiation stove, arose the idea for the Free Flow hot air stove.

It took only a week from the idea to the first prototype. The heating power was overwhelming. Thanks to the Free Flow, Darnell’s draughty home became equally warm everywhere. Up to today, he heats his entire house in Vermont with a first generation Free Flow.

On a business trip in the early 1980’s, the entrepreneur Erhard Knöfler, discovered the Free Flow in a Canadian lumberjack bar. At that time, the Free Flow was manufactured in Canada. Erhard Knöfler met Eric Darnell and a short time later, he first acquired the European distribution rights and later on also the patent of the stove.

Erhard Knöfler established the sales company ENERGETEC and called the Free Flow stove Bullerjan®.
Since then, the Bullerjan Free Flow has proven itself many thousand times over. In Europe, the Bullerjan became famous for its quality and unique heating performance. There was no large advertising budget – the good reputation of the Bullerjan® brand arose predominatly through recommendations of satisfied Free Flow users and through the passionate dedication of the first Bullerjan distributors.

Since the generation change of 2012, the company today operates under the name of Bullerjan GmbH. It is the vision of the company to continue and keep alive the creativity and the pioneering product approach of Eric Darnell and the competent entrepreneurial spirit of Erhard Knöfler combined in Bullerjan GmbH.

1977: Eric Darnell and his first production partners Bob and Sherm Wilson