Heaven help me - I've just bought a delta kit :-)

[curious aardvark]

Absolutely does not need to blow out a candle.
Cooling on a 3d printer doesn't need to be particularly powerful. Just needs to be able to cool the filament a few degrees faster than it would normally.
So no, won't blow out candles, won't blow down houses of straw or sticks.
But it will cool down filament enough to significantly improve quality of prints. Which is actually, what it's for :-)

Plus the filament on a delta cools down faster than on most other machines - the stuff I've been able to print without a fan has proved that.
The extra cooling this adds does the job :-)