They are almost the same, but not quite. BLDC motors (and their drives) use a trapezoidal wave form on the pseudo-AC power, so that ends up giving them higher torque density at lower speeds, so the motor can be smaller if that's your operating point. But the trapezoidal waveform then can cause added heating at higher speeds. PMAC motor (and their drives) use a sinusoidal waveform and the windings are more distributed. So compared to BLDC at low speed, the motor size would be larger, but is much better at running at high speeds in comparison.
Since HVLS stands for High Volume, Low Speed, I would think that BLDC would likely fit the bill in terms of its "sweet spot". PMAC would be fine too, but for continued use at low speeds, the torque-to-weight ratio is likely higher and since you have to hang the whole thing from the ceiling, that would give the edge to BLDC.
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