The cooler you originally used is great for fluid, but sub-optimal for the purpose of drying air. Even after rotating it so the entry and exit are located correctly, the design of the cooler itself will still trap liquid water which the air you are attempting to dry must then percolate through. Whether you keep the one you have or get the 13315, both need to be oriented so the air enters the top and exits the bottom, then goes through the condensate separator (which needs to be lower than the cooler exit), and then into the tank.
You indicated previously the cooler was dropping the air temp from 120 to 25, which sounds like roughly ambient for Canadian July. If the air leaving your cooler is already at ambient, there is nothing to gain from adding a fan. If the air is still not sufficiently dry for your purposes, you need to add a refrigerated air dryer and/or dessicant dryer to your system.