I replaced the switch of the AirKing bathroom exhaust fan with a countdown timer.

However, even the timer is working as expected, I noticed a drop in the fan power, it does not blow as much air as it used to blow. So, I think the issue may be related with the output of the countdown timer. The manual (see below) mentions an output of 500W. But, I am not sure what is the wattage of the fan. Would you agree that this is the reason for the drop of power? Can you recommend me what should I look for when buying the right countdown timer for a exhaust fan?

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    A typical bathroom exhaust fan will consume far less than 500 watts. If I were experiencing what you describe, my first step would be to challenge my perception - find some way to test the components. Measure voltage before and after the switch while it's on, or use paper to gauge how much air is moving through the fan. It will be inconvenient to take the timer back out to connect the fan directly to get the comparison, but I feel it necessary in a situation like this. If there is indeed a power drop, I'd suspect the timer of being faulty before I would accept that there is a power limitation. – wes Jan 3 at 19:35
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    I correct myself - after googling, I found a few mentions of other people noticing their fans slowed down after installing this timer. I haven't found details yet, so I'm not sure of the exact cause. It seems this timer doesn't simply complete the connection to the load circuit, so it can treat different kinds of loads differently. They suggest using a Leviton LTT60-1LW instead. amazon.com/gp/product/B003KYS5D2 – wes Jan 3 at 19:53
  • @wes if it wasn't completing the connection, the fan wouldn't run at all... – FreeMan Jan 3 at 20:00
  • I replaced it with a countdown timer of 1800W and now it is running at its regular speed. – kiewic Jan 3 at 22:59
  • @FreeMan When I said "simply" completing the connection, I meant working as a relay, with the control side connected to the timer. This unit appears to be doing more than that, which is less than ideal for driving a motor. I'm not sure what that might be (maybe load monitoring?), and I'm not going to go buy one just to take it apart and see what it's up to in there. If OP wants to mail me the old one, I would be happy to dissect it. My point was that, whatever the problem is, it does not make sense to conclude that it's due to a limitation in how much power it can pass. – wes Jan 4 at 4:39

This switch is for use with halogen or incandescent light fixtures only and is not designed for motor loads. Motors do screwy things to electronic switches. Get a simple spring operated countdown timer.

  • Got it, that what I was thinking, thank you so much – kiewic Jan 3 at 20:05
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    There are electronic timers that can handle motor loads out there...but they are going to use a different design that requires a neutral in the switch box. (Say, a Lutron MA-T51MN, or a Leviton LTB60-1LZ) – ThreePhaseEel Jan 3 at 20:49

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