The construction of very compact instruments is a time consuming and expensive task, which no one will make just for the fun of construction engineers. The main reason for minimizing instrument dimensions is because laboratory bench space is among the most expensive surfaces known. It counts much in terms of productivity, if it is possible to place just one bioreactor or four of them on the same laboratory bench surface...
Therefore, LAMBDA made a major effort to construct the most compact reactor available which despite of its compactness allows for excellent access to the fermentation vessel from all sides. (see also Optimized vessel design for additional information on the culture vessels, which very much contribute to this enhanced accessibility.)
Instead of piling up equipment into towers aside the reaction vessel (which is commonly done in other existing bioreactor systems), the key idea was to put all components just below the fermentation vessel. In this way, both, the bioreactor's foot print and its dimensions are strongly reduced. The sealed, water tight control unit serves at the same time as a stable holder for vessels of all volumes.
Additionally, many cables, connections, tubing as well as the heating source disappear inside the control unit. This makes the bioreactor vessel environment much less complex and the work with the LAMBDA MINIFOR bioreactor/fermenter much more convenient. It spares also a lot of work doing all the connections for each experiment (setup and dismantling time). (Have you ever seen a picture of a fully connected bioreactor on leaflets of any bioreactor producer? You can guess why not...)
Much effort was also invested to keep a perfect overview of all parts of the bioreactor (see also maximal accessibility and visibility).