Ventech 6" fan fried

Yesterday my grow room exhaust fan was making its typical loud ass rattle noise. Later in the day I was walking by and heard it really struggling. I hurried in to the room and found it to be just about seized up, hot, and not exhausting any air! This is no good as my 600 watt hps is the fan cooled type.

I quickly turned on the room light and switched off the hps. Luckily I had a duplicate fan unused that the seller on amazon sold, lowballer, so I grabbed a screwdriver and switched them out. They sent a replacement since I previously complained about the noise, just never got around to sending the defective unit back. I have the fan setup to hang from bungees from the supports for a drop ceiling. I wonder if I didn't come across the issue so soon after it happened what would have been the outcome - fire? Light failure? The room temperature was still about the same as always, and the floor fan used for circulation was still running.

What brand exhaust fan do you use? Do you have a spare for this possibility? Is there something that could be set up so as to notify of inadequate air flow?

I know some people who like the VENTS-US 327 CFM duct fans, sold at Home Depot. You can pay a lot more and if they have a (real) high MTBF rating they may be worth it. Blowers that need to be fail safe have a built in tach which can shut things down if it stops spinning. An of course its always better to push cold instead of pull hot.

Mine lasts about 1yr running 12.5 hrs a day for my ac exhaust
It's exhausting hot air thus f n up the bearings. It's only a 80.00 swap.