Redoing one of our full bathrooms.
Better to smartify it (I.e. smart switch tied to the fan, humidity/motion sensor to trigger), or go with a physical switch with humidity built in (something like Leviton IPHS5-1LW).
I know what board this is, so I have a guess which way advice will lean. 
Also going to redo a powder room, But I think I’ll just put the loudest fan, physical switch in that one (no bath/shower.)
Any good humidity sensor and a caseta fan switch...
Smart switch:
Pros: all the usual
Cons: Ummm Price (maybe?)
Dumb switch:
Pros: Price (maybe?)
Cons: None of the smart Pros.
for Smart. 
There is another option you might want to consider. It is the manual timer switch. When activated it will turn on the fan and then turn off after a preset time.
If you read various threads about humidity sensors, you will find that they are often slow to respond, especially if they are not positioned in the optimal position. Thus, they can often turn on after the humidity has already risen higher than you want and will continue to stay on after the humidity has returned to normal.
With the manual timer, I simply tap the button on the switch to turn on the fan as I am getting ready to take my shower and I have it set to turn off again a few minutes after I get out of the shower. It might not be the best system for you, but it works well for me.
Best of both worlds. I have rules set up for a smart switch to act like a timer, but remains on if humidity is above a threshold. Handles two use cases and can be easily tweaked.
That is how my bathrooms are setup and it works great!
I use Inovelli Red switches with button rules that will turn them off automatically after 10 minutes when pressed once, and longer depending on the number of presses. A separate rule checks the humidity of the bathroom sensor and compares it to a reference sensor in a bedroom. Starts the fan as required.
[quote="Sebastien, post:6, topic:95022, full:true"]
Are you able to use the led bar on the Red as a time remaining display?
Unfortunately, that is not something that can be done on the Red, but it will be possible on the Blue 2-in-1 since the LEDs can be individually controlled on that one. I never thought about that - what a great idea!!!
@spartysh32 Take a look at this... It may help with your decision
Don't forget powering a fan is different then powering lightbulbs. I have had emails with both Inovellie and Zooz recently about what different use cases for the switches. Both were fairly blunt about fan usage. Inovelli said non of their switches except for the fan/light combo switch should be used with a fan. Zooz was fairly insistent that only the Zen30 double switch be used, but some of their switches (Zen24 and Zen71 i believe) are rated for low power fans that useless then 3 amps.
I say this because many folks install a switch and then have it periodically lockup/fail for them. I have Zooz Zen24 i think. It works well most of the time, but on 3 occasions it has locked up and i have had to powercycle the circuit breaker to rest the switch. It is great when it works.
The real problem with humidity is getting a sensor to report it fast enough. You will likely not want a battery powered device as it will chew through batteries like crazy reporting enough to make it useful or it will report late and slow down activation or deactivation of the fan. I am using an Aeotec AERQ temp/Humidity sensor. The most recent version of it should report as frequently has 4 min. A Aeotech Multisensor can report much faster, but will eat batteries or can be attached to a wall outlet.
Inovelli has publicly said they will have a new blue series fan switch soon as well. There is also the Lutron fan switch. NYCE and Sonoff report well. I have 2 NYCE's in my bathroom and a sonoff temp/humidity sensor in my halway and have them set to report on .05 change (so they update frequently) Work very well on comparative RH.
I use a fan with a built-in humidity sensor, controlled by a Sonoff zigbee switch. This works well for me, the fan will turn on and stay on when high humidity is detected and I can control the fan when presence is detected and mode is not Night, via Hubitat.
Do you know what kind of fan you have or will have after the remodel?
I'm not an electrician, but my HRV is connected from one bathroom to the next. The switches all run on 24V and each switch has a timer, 20-40-60 minutes. I'm planning to add another 'switch' but use a relay there instead. That way you can turn on the fan in each bathroom still using the manual method, but you can also turn it on from a rule.
I installed a smart switch (Z-Wave) that matches the rest of my switches and dimmers, but this would -I think- work with Caseta or any other integrated smart switch.
I then made a rule that when the switch is manually turned on, it stays on for x minutes (where x depends on half- or full-bath) then turns off. If the switch is tapped up (on) again, the timer resets. Of course, you can turn the switch off manually, and the rule will cancel and the switch will stay off. For me, that was simpler (read: quicker and cheaper) than adding a humidity sensor and figuring out what the values should be to trigger and cancel the humidity rule.
OTOH, I got into the shower just yesterday without activating the fan, which is rare, but highlights the need to add humidity sensing somewhere toward the bottom of my HA to-do list.
Using this fan, which has meh reviews.
Hampton Bay BPT12-13D 70 CFM Ceiling Exhaust Bath Fan https://a.co/d/iX10C56
What paddle switch, humidity (maybe motion?) sensor should I use?
Thinking this: Enbrighten, White & Light Almond, Z-Wave Plus Smart Fan Control, Works with Alexa, Google Assistant, 3-Way Compatible, ZWave Hub Required, Repeater/Range Extender, 55258 https://a.co/d/7Boi7h6
Is this good for amp draw?
Would like a reasonable motion, temp, humidity sensor. I normally use Hue, but that doesn’t capture humidity.
You don't want a fan switch...you want a standard on/off switch. The one you linked is meant for controlling AC ceiling fans. I use these switches although they weren't $50 when I bought them .
I'm a fan of Zooz products. Their ZSE40 is a 4-in-1 sensor...just be sure to include it unsecured.
The problem with humidity sensors is that they are slow to respond to humidity changes such as will occur when you take a shower. Also, the humidity sensors are notoriously inaccurate.
What I did in my bathroom is install a timer switch that allows me to run the fan for a specific amount of time.
https://www.amazon.com/Pass-Seymour-RT2WCCV4-Legrand-Operation/dp/B01N7T9QBV/
The switch will handle up to a 1/6th HP motor. You can set the fan to run for 10, 20, 40 or 60 minutes. It remembers the previous setting. So before starting my bath, I start the fan and it turns off automatically. I have a large master bath and the fan normally runs for 20 minutes. With a smaller bath or a larger fan, 10 minutes might be sufficient unless you take lengthy showers.
I think that really depends on the humidity sensor and placement. I have some standalone Zooz ZSE44s that will cut the fan on around the same time that the water finishes warming up. They are mounted directly above the shower doors. It took a little monitoring of 3 or so shower cycles to get the "turn on" and "turn off" settings dialed-in.
The advantage is that they only run for as long as I need them to. This setup coupled with motion sensors and automated lighting is the closest you can get to a fully automated solution. Only problem I haven't solved is turning the fan on when someone is dropping the kids off at the pool. I walk in, turn the shower on, do my thing, and walk out. The fans and lights take care of themselves.
I use the NYCE sensors in my bathroom and they update fairly quickly. Combined with a smart switch for the exhaust fan.
The Nyce sensors seem to have good battery life and the batteries are standard AAA (at least in the round sensors that I have attached to the ceiling).
Download the Hubitat app
