AC powered humidity sensor?

I don’t (quite) yet have my ST hub. (It should arrive this week), but I’m already thinking of ways I can use it for something beyond an android powered light switch.

One of those areas involves my children. They have this really bad habit of taking hot steamy showers, but not turning on the bathroom exhaust fan. I know I can just wire the fan to the light with a conventional switch, but what fun is that? Anyway, it doesn’t really solve the problem, as the bathroom is still full of steam when they turn off the light.

What I’d like to do is to get some kind of z-wave humidity sensor that’s powered by A/C (not batteries), and 2 z-wave on/off switches. On on/off for the light, and the other for the exhaust fan. Then, set up some kind of ST app or rules so that:

  1. If the bathroom light is on, and the humidity goes over a certain threshold, turn on the exhaust fan. (Don’t turn on the fan if the light is off – the assumption here is that in this case the humidity isn’t from inside the bathroom and the fan wouldn’t do any good.)

  2. When the humidity drops below a certain threshold: if the exhaust fan is ON and bathroom light is already off, turn OFF the exhaust fan.

  3. When the bathroom light is turned off: if the exhaust fan is ON and the humidity is already below a certain threshold, turn OFF the exhaust fan.

I’m sure I could manage the rules with a bit of dev work, but I’m not sure what kind of device to use for the humidity sensor.

Is there a z-wave sensor out there that can be powered from A/C, checks the humidity fairly frequently, and is fairy accurate for humidity readings?

It doesn’t have to be accurate in terms of human readable humidity, as long as its reliable in saying "it’s more humid now than it was before.) (for example: a humidity reading of 1 through 10 should be good enough for this.)

I’d also like to it check the humidity fairly frequently (which is one reason for it to be A/C powered instead of battery powered.) It won’t do much good if it only polls the humidity every 30 minutes! Every 2-3 minutes would probably be sufficient.

Finally, I’d like for it to be z-wave for the simple reason of compatibility. I don’t know what tomorrow brings, but it seems that z-wave (at least) is here to stay. (Perhaps zigbee will stay as well, but so far it appears that zigbee is the betamax to z-wave’s VHS.)

Thanks for any advice,

I know the fun of using Z-Wave everywhere, but as a general rule, unless there is a need for integrated automation, go with the basics. I’d recommend just sticking with something like these standard humidity sensors. In the long run you’ll be better off.

Aeon multisensor can be powered via a mini usb cable. It has a humidity sensor built in.

A less complicated (and probably less expensive) approach is to replace the fan with one that includes a humidity sensor to control the on-off. Then you just hard-wire the fan on, and let it do its thing. Delta makes these that operate down around 3 sones, so they virtually silent whether off or on.

I know - it’s not as fun as a Z-Wave solution…

You all are taking all the fun out of this. :wink: Actually, I had (in the past) looked for humidity controlled switches (like the leviton one mentioned in the first reply), but never found them at home depot or lowes. (For some reason, it never occurred to me to search amazon.) I suppose I’ll end up going that route.

Now I need to come up with another idea to “prove” to my wife that this whole home automation thing is a good idea. She was impressed with the exhaust fan idea.

Motion sensors that turn on lights is nice, but there are also times when turning on a light is a bad thing…

It’s a catch-22…the system becomes more useful as you add more and more devices to it (the network effect, as we say in the tech industry). I don’t have a single killer app that I use my system for but I can’t imagine going back to a life where I can’t control my home in so many ways, from lights to locks to my Roomba, and so on.

That being said, safety and security features generally carry a high WAF, especially when there are kids involved. Look at projects like automatic hallway/bathroom/kitchen lighting if a child (or anyone for that matter) gets up at night or projects which increase internal or external security. At my previous house I used SmartThings to make my garage door highly secure but added some automation features.

Actually there are a number of killer automation items that really do make a difference depending on your setup.

For anyone in a condo, a rental property, or that has a maid or other individuals coming in and out of the home, the ability to have an integrated smart alarm system is invaluable. On the door side, a Z-wave enabled lock that reports on unlock by PIN basically allows you to log entry and exit. Using the door PIN also allows you to determine how you want the rest of the system to be alarmed. In my case (a condo), when the building maintenance people or house cleaner comes in, I disable the alarm system, but I leave on the internal cameras. This allows me to know and check on what’s going on while they are in the suite. Certain areas are still alarmed with motion sensors (bedrooms) when the maintenance guy is in, but not alarmed when the house cleaner is there. Some areas are ALWAYs alarmed like the area where our personal safe and jewelry is stored as no one but my wife and I need to go there. I can also set and remove the PINs so they only work certain days, or certain hours of the day. No keys floating around, no worries about un-authorized entry.

For individuals with rental properties, you can setup the sensor to say that you want the HVAC unit to go to a different ambient set point when a patio door or a window is open. In that way you can control electrical costs for heating/cooling. You can automatically set and disable door PINs after a guest has left their stay on the property, automatically report if there is water on the bathroom floor, under the sink or by the washer/dryer so that you can get the remote building maintenance people in to look without having to do a physical inspection every week.

For homes with kids, simple things like have a room turn off all the lights when there is no movement can be done with standard motion sensor light switches. But as you’ve mentioned not having them come on during the day or at different times of the day, is tougher (but the new switches can also do this). So having the system say, act as a motion sensor for lights from sunset to 11pm, but don’t turn on after 11 till sunset unless there is a manual touch of the light switch is a great way to control electrical costs if you have kids (not that you’ll offset the cost of the sensor or switches but hey), or avoid having lights turn on a wake everyone when you come in late or want to check in on their rooms.

My favourite right now is just using the ST presence sensors to “sweep” the house on mode changes. So when I’m leaving - do a sweep and ensure all the lights are off, the cameras and motion sensors are armed, reduce the furnace set point and advise me if anything is out of whack or detected on the moisture sensors.

At night when I DoubleTap my bedroom light switch, sweep the house and ensure all the other lights are off, set the system to night mode (arming outside motion sensors), activating outdoor camera recording and flashing my bedroom light if a window or door is left open/opened.

Each home will have a unique combination of features that will enable better living. I know I travel easier knowing I can check the system state, report a water leak to the property manager before it floods multiple units, check my cameras and review if something seems out of place when I get home, and avoid running round the place just to shut lights off at night.

The killer feature for my wife, was having an entryway light come on as we enter the suite after sunset, and flash whenever someone knocks at the door.

[quote=“mmlabelle, post:7, topic:8690”]
The killer feature for my wife, was having an entryway light come on as we enter the suite after sunset, and flash whenever someone knocks at the door.
[/quote]How does it detect someone knocking at the door? I’d think anything that would detect knocking would go nuts during a thunderstorm (or anything else that creates vibration.) Also, how do you get it to flash a light?


The Flasher. Was one of the first apps in the IDE.

It can be a bit touchy under certain conditions, but to be honest it has never been a problem. We simply have one lamp in the living room that flashes 3 times. Really helps when you have the music or TV on loud.

Of course you will need a multi-sensor or something similar on the door. You can also tie it to a motion sensor I believe, so if you had something watching the outside of front door area you could avoid the false-positives and know when some is arriving before they even get to the door.

Look it up under MySmartApps/Template/Convenience/The Flasher

[quote=“mmlabelle, post:9, topic:8690”]
Look it up under MySmartApps/Template/Convenience/The Flasher
[/quote]oooh… that’s neat. Extremely simple, yet it opens up all kinds of ideas in my head.

One thing I’m noticing about z-wave and ST is that it’s not really a “finished product.” It’s more of a bunch of parts and pieces waiting to be put together. On the one hand, that makes it considerably more powerful or flexible than a canned solution (if a person is willing to put everything together and do a bit of work.) On the other hand, I think ST would be a poor product for someone looking for an already “finished product.”

Yes there is a “knocker” app now built into ST and also the code is available for the IDE - it is fairly robust and I use it on three of my doors and vary rarely get “accidental” notification of a “knock” it also takes into consideration when the door was opened/closed based on the ST MultiSensor… Great functionality!!! And yes - it can flash your lights! If you have a Hue setup it can change the colors of a light and flash too - that is how I have mine setup… Red for someone at the front door (via motion) red flashing for a knock on the front door, and same for the back door and side door with blue and green respectively… (I am even so lazy I put drop cams at each so I don’t even have to leave the computer to see who it is…) I have kwickset locks on all doors and it if it someone friendly I just remotely unlock the door and in they come… Pizza guys are still not trained yet :smile:

On your humidity sensor / question… I have three different kinds I am running and using for the same purpose as you desire… The Aeon multi sensor is probably the best for the bathroom (which is what I am using) because it is outdoor rated. i.e. it is less affected by the steam then the alternatives. And I have it setup so that when the humidity is 3% greater than the humidity in the house (determined from my NEST) then it turns on the bathroom window fan until it is the same - no more super steaming showers/bathrooms. And the batteries are just fine - more than 6 months on 4 AAA doesn’t bother me. It can be plugged in but I have it in the center of the bathroom ceiling (it doubles as a thermostat and motion detector) to turn the bathroom lights on and off) The only issue I have with it is that it only samples humidity every 8-10 minutes or so… A bit annoying since I like instant on/off for everything… The other humidity/temperature sensors that I am using are NetAtmo. They are very accurate but have a similar issue - not instant for measurements. The latest creation that I am playing with for this is an analog barometer that I have wired to an ST multi sensor - this is giving me “true” instant on/off but no digital configuration…

Hope that helps - all of the alternatives above do work and do work well!!! I use the NetAtmo in the kitchen for when it gets too hot or too humid from cooking and it then turns on the kitchen fans to move the air around the house… Is always nice when the spaghetti water is boiling and on come the fans automatically - then off as we sit down to eat :smile:

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