Seems like CPU Cooler Manufacturers are not posting the TDP Ratings of their products any more.
Normally I am able to locate the TDP Ratings in Retail Advertisements or reviews.
Found this review that mentions the TDP Rating of your CPU Cooler: https://www.eteknix.com/deepcool-ak620-digital-cpu-cooler-review/
DeepCool AK620 DIGITAL features six pieces 6mm all-black heatpipes with raised copper coldplate to maximize heat dissipation to overall 260w TDP which supports even overclocked CPUs for mighty gaming performance. AK620 DIGITAL carries a thermal paste in package, please apply it on after removing the protective film of coldplate.
If you can only fit one Fan see if that is enough to prevent your CPU from overheating under stress by using OCCT stress test.
If the CPU reaches overheating temperatures above 89c then switch out the fan and install a HIGH CFM Fan with a rotation around 4000 -5000 RPM. That should help quite a bit in cooling your CPU than using a regular CPU Fan.
AMD recommends you use a AIO Liquid CPU Cooler for this processor since it has such a high TDP Rating of 120 watts.
Since your Air CPU Cooler is rated at 260 watts it should be sufficient enough to prevent the CPU from overheating under heavy loads but I imagine with more than one fan attached though. So you will need to see if one fan is sufficient or not by stressing the CPU and checking the CPU Temperature.
From AMD Specs concerning your CPU:
Default TDP: 120W
Recommended Cooler: Liquid cooler recommended for optimal performance
Max. Operating Temperature (Tjmax): 89°C
