The VT1 kiln kit is aimed at woodturners and other woodworkers requiring timber with a consistent moisture content and who are using shorter pieces and low volume. This kit is just the drying control unit, you will need to construct an insulated kiln box yourself.
In terms of the amount of wood you can dry at the same time, it will differ depending on the dimensions of the boards/planks, but if you are drying 50mm thick boards you could dry about 0.5-0.6m³ of wood in a 1.5m³ cabinet. Timber supports and space for circulation have been taken into account.
The Sauno kiln shortens the maturing process from years to weeks. It produces timber with less cracking and more stability than other drying methods. The drying process is quick and economical, which is a large benefit for the woodworker.