The auto-heater applies the heat at the last possible point before the air enters the Aeron; as a consequence there is absolutely no loss or waste of heat, as would be the case if the air were heated at some other point and then passed through the hose to the machine. It is very easy to understand that if air heated before entering the hose retained sufficient heat to be of service when reaching the nozzle, it would be so hot that it would destroy the hose. In the only practical way, the auto-heater maintains the heat in the air at the proper degree till the spray reaches the work.
The auto-heater is light, yet rugged in construction. It has no exposed contacts. The conductor wires run through the air hose. It can be attached to any style of Aeron without difficulty. There is an automatic cut-off furnished with every auto-heater. Placing the Aeron in the cup holder, or hanging it on the hook, automatically cuts off the current--picking up the Aeron automatically turns on the current. This automatic control effects a great saving in current. As a protection against overheating the auto-heater is equipped with a fusible safety disc, which melts, allowing the air to escape, if current is left turned on by accident when the Aeron is not in use. This safety device operates within four minutes. Several extra discs are furnished with every outfit. The auto-heater can be connected to any electric light socket, and consumes only 250 watts current when in operation.
The construction of the auto-heater will be understood on reference to Fig. 91.
Another interesting heater is supplied by the Airostyle & Lithos, Ltd., a number of which are in use in this country Its general form can be seen on reference to Fig. 102, page. 165, which shows a gas-heated type. The same heater is also supplied either electrically or steam heated.
In all types it has the same general features, namely, a water-jacketed colour pot, a special coil for heating the air supply, which is afterwards passed through the water jacket for the dual purpose of raising the temperature of the jacket and damping down the air temperature at the same time. To a convenient standpipe the hot air is carried and distributed to the pistol, and also to a special jacket round the colour tube.