Do ECM machines need ventilation?

ECM machines are not ventilated like a conventional induction machine. Contamination with air-borne magnetic materials would be difficult to remove and could lead to premature machine failure. Conventional BLDC machines, some of which are open chassis designs, share this feature.
E-circuit motors can be cooled passively or actively by air or water depending on the. Water cooled E-circuit motors have demonstrated remarkable performance. But conventional TEFC or passive cooling is normal for an ECM machine.