An Exodraft chimney fan RSG provides a controllable negative pressure along the full length of the flue and chimney.
 
A fail-safe system is fitted in the fan which automatically measures the velocity of the flue gases. Only when the velocity exceeds the preset and safe level can the gas appliance be used. The fail-safe system prevents any spillage from the gas appliance as well as any leaks of CO and other poisonous gases. Fan type RSG is installed on the external wall and thereby enables a gas appliance to be installed in a room with no chimney. The power of the fan will allow for long horizontal flues up to 15 meters. A silencer type SLR is available as an accessory for the fan type RSG.
 
The built-in pressure switch in the chimney fan is wired to the appropriate exodraft control unit which supervises the fail-safe function. Only when the draught exceeds the preset and safe level can the gas appliance be used. The fail-safe system will prevent any spillage of combustion products from the appliance when the fan and the controller are commissioned correctly. In case of insufficient chimney draught, the heating appliance will be shut down.