Hello to this forum,

For a house need totally unrelated to aviation I'm in a search
for a VERY powerful fan. After searching for what's avaliable
on the general market (either huge or weak blowers) my mind
wondered "outside the box" (or, rather, above the ground) and I
remembered the RC models engines. After some "googling"
(and checking what's avaliable on ebay) I'm considering to use
the "Lander" 64mm EDF+motor. It looks both powerful and compact.
But the main obstable I see to using this component is: as opposed
to few minutes of operation during a flight, my intended use for it will be
firmly on the ground and for many hours in a row for few days (instead
of batteries I'll have to get 12V 60A power supply). Which brings the main
question: how capable is the EDF+motor combination of a prolonged
operation? From looking at the specs I saw that the max. power is limited
to about 10 Sec and slightly lower power is limited to 1 min. Is there
any table/graph/rule of thumb by which I can calculate at what fraction
of the max power can the EDF be safely operated for a VERY long time?

What are its limiting factors:

1) Bearings wear?
2) Ablation of rotor blades surface causing it to become un balanced?
3) Some other pards deform over time?

Another type of considerations are thermal limits: since I saw EDFs
sometimes mounted inside the fuselage, that means the air flow
of the fan is sufficient to cool the fan+motor, am I correct in this
respect? How about the ESC: does it requires active cooling (that is, must be
mounted to have the airflow over it)?

Thanks in advance for any info,
kaza.

P.S.: I'm aware of the noise problem, it'll be solved.

Don't even think these will work for continuous use.  If you don't have AC power but do have 12V look at automotive fans.

AltaTed

if by powerful you mean high volume look at a squirrel cage. For pressure a lobe pump (roots blower) is hard to beat, they're built to run 24/7 for years. There are also 2 stage blowers.

Thanks for the reply, Alta Ted,

Not even at a fraction of the max power, say 1/2 or 1/3 or 1/4 of it?
What is the order of magnitude of lifespan (flight hours or engine hours) of these types
of motors+fans combos in normal flight operation?

All other options looks REALLY bulky.

TIA,
kaza.

I think it can be done but you will need to have a combination that is running at about 50% of its actual capability while running flat out on your power supply, especially in Israel with the temperature variations.

The Lander fans are no use, the motors are not going to last an hour constant running let alone a day, cheap chinese is not what you need.

If you can feed the fan with 14-15v and up to 50A supply, I can build you a 70mm CNCalloy fan with a very tough motor that will run for extended periods easily. The fan housing will be CNC machined alloy, running a very tough German made Wemotec rotor and an ARC motor. On 14.5v this setup will pull around 45 amps/650 wattsand provide around 1.2kg static thrust or so out the back. The motor is capable of running at 80-90 amps constantor 1800-1900 wattsin the air for 5 mins, so with the heatsinking properties of the fan housing and a heatsink I think you should be able to run it for hours at 45A.

Its the only option I know of that will give you the headroom, if you run it at 13v from a regular 13.8v switchmode power supply you will be down under 40A and even safer. What sort of air volume do you need from the fan? You can email me <span style="color: #0000ff">HERE</span>if you dont want to talk about the application on open forum.