Humidity Sensor Options

rampantbunny

I have no automation in my house at the moment, but this is something I plan on changing given time.

First up, I'm looking to bring some sort of smarts to an MHRV (heat recovery) system.
The MHRV unit allows for manual boost of fan speed using momentary switches located near wet rooms (you would boost if going in for a shower etc). I've no manual switches installed to date as I'm not gone on the way they look.

I do have a duct humidity sensor (probe type) back at the MHRV unit itself. This works but there's a delay, as the humid air has to travel back along the ducting before reaching the humidistat. Delay is not ideal.

So I want to install some wireless humidity sensors in the wet rooms themselves. I'd like to hide them inside the extract vents because these vents are located in the areas where humidity will be generated. Of course the vent housing is metal so not sure this will help wifi signal.
I'd like these remote sensors to trigger the MHRV boost back at the unit itself.

I've looked at the sonoff sensors but I believe they need mains power, plus I think they need firmware update to support the likes of OpenHAB...could be wrong on this because it has been a while since I checked.
I won't be able to route cables for power so looking for battery operated sensors if possible.

Any suggestions?

Also, to do the above, will I need a smart hub (not against one, because I do plan on expanding functionality with time).

THE ALM

rampantbunny wrote: »

I have no automation in my house at the moment, but this is something I plan on changing given time.

First up, I'm looking to bring some sort of smarts to an MHRV (heat recovery) system.
The MHRV unit allows for manual boost of fan speed using momentary switches located near wet rooms (you would boost if going in for a shower etc). I've no manual switches installed to date as I'm not gone on the way they look.

I do have a duct humidity sensor (probe type) back at the MHRV unit itself. This works but there's a delay, as the humid air has to travel back along the ducting before reaching the humidistat. Delay is not ideal.

So I want to install some wireless humidity sensors in the wet rooms themselves. I'd like to hide them inside the extract vents because these vents are located in the areas where humidity will be generated. Of course the vent housing is metal so not sure this will help wifi signal.
I'd like these remote sensors to trigger the MHRV boost back at the unit itself.

I've looked at the sonoff sensors but I believe they need mains power, plus I think they need firmware update to support the likes of OpenHAB...could be wrong on this because it has been a while since I checked.
I won't be able to route cables for power so looking for battery operated sensors if possible.

Any suggestions?

Also, to do the above, will I need a smart hub (not against one, because I do plan on expanding functionality with time).

The likes of the Xioami Aqara Humidity sensor might work for you. Just received one in the post to trial and you will need a hub for this to work, I have the smartthings hub which I plan on using. Powered by a cr2032 battery so no cables required.

rampantbunny

THE ALM wrote: »

The likes of the Xioami Aqara Humidity sensor might work for you. Just received one in the post to trial and you will need a hub for this to work, I have the smartthings hub which I plan on using. Powered by a cr2032 battery so no cables required.

Thanks, will check out the Xioami items for sure.

Also, just came across http://wirelesstag.net/. Nice small devices, battery powered touted to last potentially years depending on use. Need a local 'Ethernet Tag Manager' which receives the signal from the sensor before processing/sending out.
Not sure if any interface for smart home hub connectivity. TBH - complete noob at this so might have to just spend some money and test things.

THE ALM

Can confirm that the Temp/Humidity sensor connected ok to the smartthings hub and is reporting humidity, temperature, atmospheric pressure and battery level ok.

Will see how it runs over the coming days.

rampantbunny

How often does it poll humidity...I wouldn't expect it to be real time as it would zap battery life. Is it set or configurable?

THE ALM

rampantbunny wrote: »

How often does it poll humidity...I wouldn't expect it to be real time as it would zap battery life. Is it set or configurable?

Doesn't give a poll interval in the smartthings app. Looking at the smartthings api it gives a check interval of 7320 although what that is in real terms is hard to say and no way of changing it that I can see.

Reading up on it it would appear that any significant change in readings will trigger an update. If I check the list of events there is no set time for an update and the readings vary from 3-4mins to 60mins.

rampantbunny

THE ALM wrote: »

Doesn't give a poll interval in the smartthings app. Looking at the smartthings api it gives a check interval of 7320 although what that is in real terms is hard to say and no way of changing it that I can see.

Reading up on it it would appear that any significant change in readings will trigger an update. If I check the list of events there is no set time for an update and the readings vary from 3-4mins to 60mins.

I'll be getting one anyway regardless and will see how it goes.

Question (and it is a very basic one)...you have a SmartThings hub. Did you need to get a Xioami hub/gateway also?
I'm unsure as to the way smart devices (not just Xioami) communicate and mesh together for automation. Essentially, if purchasing sensors from different manufacturers is there a need to also purchase their gateway - or is it a case that if zwave/zigbee then these sensors will work with other hubs supporting those protocols?

THE ALM

rampantbunny wrote: »

I'll be getting one anyway regardless and will see how it goes.

Question (and it is a very basic one)...you have a SmartThings hub. Did you need to get a Xioami hub/gateway also?
I'm unsure as to the way smart devices (not just Xioami) communicate and mesh together for automation. Essentially, if purchasing sensors from different manufacturers is there a need to also purchase their gateway - or is it a case that if zwave/zigbee then these sensors will work with other hubs supporting those protocols?

No need for the Xioami hub as the sensors will work with the smartthings hub. If you are looking at various sensors etc then check the smartthings forum to make sure they are compatible, a lot are. It may mean having to add a 'device handler' to get it to integrate as it may not be compatible straight out of the box but chances are somebody has created one for a particular sensor etc.

Keep an eye on Amazon as they regularly have the hubs and starter kits at half price, this is the reason I purchased mine. Also check adverts, donedeal etc as people regularly will buy the kit as it works out cheaper but may have no need for a second hub.

Having said that I also have the hive heating hub, a philips hue hub, a harmony hub and a rpi3 running home assistant. Smartthings can control all these without the different hubs but you will tend to find that the individual companies, philips hue for example, do a better job of controlling there products through there own hub and app.

As you say, most of these systems will communicate through zigbee, z-wave, wifi or bluetooth and the smartthings has all these built in to its hub so a good chance it can control a lot of devices just maybe not a fluently as the native system. This is not true of the other hubs as Hive will only control Hive products (it has added Hue control recently) even though it uses zigbee, hue only controls hue (Ikea Tradfri can be added to hue along with a few other lights). These hubs tend to only support one protocol be it z-wave or zigbee and will not control all zigbee or z-wave related products.

For automation, smartthings may do all you need, if not and the automation is a bit more complicated then the likes of ifttt or stringify can link several actions together to get the desired result.