Kiln or drying room air is drawn into the space heater from a lower panel and is circulated around the combustion chamber, where it is heated before being vented into the kiln/drying room via the ducts on the top.
The combustion gasses never mix with the clean heated air as the two chambers are completely separate.
Additional ventilation ducts can be added. However due to the large built in ventilation fan hot air will be circulated over very large areas.
Its very simple. Paper or cardboard with smaller kindling laid on the grate. Load with larger wood and in minutes heat already being produced.
Simple cleaning and maintenance. General maintenance is the removal of ash when required and once or twice a year a general clean and chimney sweep.
The diagram below shows the configuration of a basic dryer system, with access to the dryer chamber from either front or side.