the amp draw is dependent on the motor and the fan blades used. A change of the blades will make a big difference on the amp draw. The good old mabuchi motors that are used are not very good and draw quite a heavy draw. I have switched over to computer fans for all my vent motors (even my fantastic fan). The amp draw in very low and much quieter operation. I built a housing for the stove vent with 2 smaller fans with a switch to select 1 or 2 fan plus a speed control. My old fantastic fan blade self destructed and I replaced the fan motor and blade with a Bitfenix 230mm fan that moves 160cfm and draws .3 amps(about $20). The cost of these fans are much lower than the cost of replacement motors from a rv shop. Being a computer tech, I have a large selection of fans to choose from from dead power supplies and cases.