Long description
This shows a metal box standing on two slightly protruding legs. It is about twice as wide as it is tall and is relatively thin from front to back. The key element is a number of labelled ‘high density thermal blocks’. These are shown containing electric heating elements and also labelled ‘vertical airways’. The set of blocks are surrounded with labelled ‘insulation’. At the top of the heater is a labelled ‘damper’ and to the right a set of ‘charge and output controls’.