WorkBench Fume Extractor Fan

After many years of breathing solder fumes and ending up with lung damage, finally this is what I've come up with.
Both sides of my work bench have fans on the end of 90mm PVC pipe. The other end is outside and has a 120mm fan.
Each bench fan has the flap held in the closed position with small disk magnets. When one is opened, it is held in then open position by the disk magnet holding on to a screw on the side of the pipe. The cover flap operates a microswitch to turn on the fan.
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