Okay, I don't know how I missed this project.
First of all, great idea! I have that same ducted fan unit in a completely different project of mine.
Second, the manufacturer may say that the fan unit can take more than 27,000 RPM. Don't pass 30,000 RPM. I was using a Feigao 12XL and 24v lead acid through a Phoenix-60. Here are some numbers after the fan was running for a minute or two:
-21v
-110amps
~2300 watts (3HP)
-~25,000 RPM
And yes, the Phoenix-60 with some copper heatsinks and 6 extra capacitors was pushing 110amps. Unfortunately my watt meter couldn't, and was smoking/melting a bit.
I've already broken two of the fan blades while keeping the fan around 25,000 RPM tops, without a load on the fan (just spinning the fan in open air). That said, my setup is a bit different, so that could have cause the blades to break, or it might not have.
Without modifying the unit, it can only accept motors with a diameter up to about 37mm. That means Neu 15xx series motors won't fit, unless you cut the shrouding around the motor.
If you don't have the ESC already, look into the OEMRC Sentilon 100amp 12s airplane ESC:
https://www.unitedhobbies.com/UNITED...idProduct=4691
https://www.unitedhobbies.com/UNITED...idProduct=2169
And let me say it again, don't spin the unit too much past 30k RPM.