Zwave humidity sensor

[MWareman]

Is there such a beast? I've tried to ring one, to no avail...

 

Background: the humidistat controlling my humidifier is awful! When I set the dial, it really could be +/- 20% off. I'm looking for a relatively accurate not battery powered method of getting accurate, reliable humidity measurements into the ISY. I already have a solution for controlling a relay to control the humidifier, so I just need the sensor side of things.... My goal is to have the ISY adjust the target humidity level based on the outside temperature (or more accurately the temperature difference between inside and outside).

 

I've spoken well of the CAO gadgets in the past - but I've discounted them for this purpose. The cloud dependency makes it not suitable.

 

Ideas?

 

Michael.

[mwester]

My aeon labs multisensors have humidity sensors... but I can't say that I've ever paid any attention to the accuracy or precision of same.  Nevertheless, they're useful enough that it might be worth trying one.

[MWareman]

I'll check that out... I have a couple of those and I forgot they reported humidity.

 

I'm tweaking the parameters to see if I can get the reporting to be much more regular than default, and logging it to compare with other sensors. I'll give it a couple of days to see how well it does.

[Teken]

I'll check that out... I have a couple of those and I forgot they reported humidity.

 

I'm tweaking the parameters to see if I can get the reporting to be much more regular than default, and logging it to compare with other sensors. I'll give it a couple of days to see how well it does.

 

The first thing is to confirm the level of accuracy the unit provides by default. Once this is known you can adjust the sensor to compensate for any immediate drift.

 

The tried and true method is to take some table salt and place it in a container / dish. Add water so the salt becomes like wet sand. Once that has been achieved stick the sensor in a zip lock bag or similar sealed container.

 

With this in place the relative humidity will be 75% RH.

 

Depending upon how long and how accurate the *default* readings are. You will simply adjust and compensate until it reads 75% RH. You will want to perform this test at least three times to ensure the multi sensor is reading accurately.

 

This is how I test, validate, and confirm all of the humidity sensors I have on hand including any of the really expansive digital measurement tools I have on hand even if the device was re-certified by the vendor.

 

As an aside what are the reasons for not using the CAO sensor? RH isn't something that is really critical and changes very quickly in a home so even with the whole cloud / IFTT thing I don't see too much of an issue?

 

Unless there are other problems and barriers you haven't shared with the group. For myself using any remote service is out of the question for me as the first line of measurement and reaction. I only use cloud hosted services as a secondary (assisting) feature for none mission critical services in the home.

 

Even then I can count on two fingers that rely on the cloud but these devices serve nothing more than a play thing in my home and HA. 

[larryllix]

I use my Venstar T7900 thermostat to measure humidity.

 

This is sensed by an ISY program that detects if NodeLink is updating from the T7900 and the reading is reasonable. If not, then the Insteon 2441ZTH in the basement is used for the house humidity sensing.

 

Using the salt method I calibrated my CAO Tags and then calibrated my T7900 from them.

 

My T7900 had some drift when new for a few weeks but I believe that has stopped now that it is a month or so old. It was calibrated against my Tag Pro (supposed to be +/-0.4C accurate) and a half a dozen digital thermometers averaged.

 

Magnesium chloride crystals is a better humidity calibration level at 33% RH. I have some in liquid form but not pure crystals. Dead Sea salts are not pure enough.

[MWareman]

@Teken, I want to use the sensor to enable my whole house humidifier when the air in the return duct is too dry, and the temperatures measured (onewire via my GEM/Dashbox) will allow an increase without causing condensation on the windows - subject to defined limits. I need the solution to be entirely off grid - no Internet dependency. I also need to be able to get the current RH sensed into the ISY.

 

I'm actually now thinking about using a CAI web control board to do this with a Honeywell HIH-4000 sensor - sending the current RH into an ISY variable. I need to think of this as an autonomous system that just runs - but integrates with the ISY just as a thermostat might.

 

Thanks for the info on calibration! I had no idea. Seems I have some work to do there...

[larryllix]

....

I'm actually now thinking about using a CAI web control board to do this with a Honeywell HIH-4000 sensor - sending the current RH into an ISY variable. I need to think of this as an autonomous system that just runs - but integrates with the ISY just as a thermostat might.

 

.....

They're pretty easy to set up. you would be done in one night for the software.

PSU and wiring, case etc, would be longer.

 

I have mine on an old modem in another building. I can upgrade it from my LAN via modem jumps.

 

I use the real time clock (Web based sync) as a heartbeat and ISY real time clock but v5 is making it redundant.

 

 

I use these variables to record the last value sent to ISY. From left to right:

MMDDhhmmss, OutTemp, OutTemp.24hrLo, OutTemp24hrHi, OutHumidity, ShopTemp, WindAvg, WindGust

 

All values x10. Need a prec=1 sent via Rest for ISY 0.1 variable resolution. I use an ISY input clone decimal creator to do the divide by 10into a 0.1 variable. Go v5!!!

[MWoods329]

Is there such a beast? I've tried to ring one, to no avail...

 

Background: the humidistat controlling my humidifier is awful! When I set the dial, it really could be +/- 20% off. I'm looking for a relatively accurate not battery powered method of getting accurate, reliable humidity measurements into the ISY. I already have a solution for controlling a relay to control the humidifier, so I just need the sensor side of things.... My goal is to have the ISY adjust the target humidity level based on the outside temperature (or more accurately the temperature difference between inside and outside).

 

I've spoken well of the CAO gadgets in the past - but I've discounted them for this purpose. The cloud dependency makes it not suitable.

 

Ideas?

 

Michael.

I use Everspring ST814-2. Works well.

 

 

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[MWareman]

I use Everspring ST814-2. Works well.

 

 

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Thanks! I'll take a look. Was hoping for not battery powered - but I could rig up a power supply. Do you know if I can mount this on the outside of a duct to sense the RH of the air within the duct? The stat I'm trying to replace does this... (Senses from the rear as an option)

[gduprey]

You'd have to mount it in the duct -- it has a "vent" on the front that it monitors air from.

 

Few notes though - you can adjust the threshold it sends updates for to 1 degree for temp and 5% for RH.  I have about a dozen of these things pread throughout the house to track ebb and flow of temps (humidity is a lot less variable) and haven't been able to set them 'change reporting' lower than 5 for RH (you set config parameter 7 to 1-byte value "1" for temp reporting and parameter 8 to 1 byte of "5" for RH -- setting to less than 5 doesn't seem to work).

 

Typically, they seem to last about 8-10 months on a set of standard AA batteries (3 of them).

[MWareman]

Thanks. I don't really like the 5% thing. I'm pretty much coming to the conclusion that zwave based is not the way to go for my use case. I think I'm going to stick with the CAI board and the Honeywell sensor. Greater resolution, the ability to mount the sensor inside the duct and CAI board outside and easy running off a power supply makes it worthwhile - and I can move all the humidity logic onto the CAI board - and have it simply report to ISY what its doing.... Plus, I've been looking for an excuse to get one...

[ISYhbsh01]

IIRC the CAI board supports only 1 humidity sensor vs. 8 temp sensors. So keep that in mind.

[MWareman]

IIRC the CAI board supports only 1 humidity sensor vs. 8 temp sensors. So keep that in mind.

Will do - thanks. Only need 1 RH sensor (return air duct) and 2 temp sensors (one also in the return air duct, the other outside) to perform the math on.

 

Michael.

[larryllix]

Will do - thanks. Only need 1 RH sensor (return air duct) and 2 temp sensors (one also in the return air duct, the other outside) to perform the math on.

 

Michael.

CAI is reported working on getting the SheepWalk SWE3 humidity and temp probe working again with their 1wire. It uses a completely  different timing setup and was hard to share the 1wire with the DS18B20 probes. (see another thread in that forum for our discussion).

 

The CAI is easy to interface with ISY and write PLC code for. It really reminds me of writing Assembler code, if you have experience with that. I liked it for that as I spent 20 years doing that, so it feels natural to me.

 

I have a 1wire adapter for my RPi that handles all these 1wire sensors and with ISYLinc??? you could stuff all the inputs into ISY very easily if that route tickles your fancy.

 

With WC8, keep your 1wire cables short. I know they are working on that, but the board version I have has no signal shaping on it and signals are right out of the chips. I suffer from high slew rate ringing on my 1wire bus from the WC8. The Maxim devices have a slower slew rate and the CAT5  line doesn't ring. Of course it's hard to tell on a scope not knowing who puts out what.  I mean to get  back at it, some year, and insert a slew rate RC to hep the signal but it is working right now without the SWE3 humidity sensing and short temp probes.

 

I may just copy your intent and get a direct wired humidity chip with some long leads on it and stick it outside up my weather post.

[MWareman]

I'll certainly post what I do... I haven't written Assembler for over 20 years (I wrote 6502 code as a hobby - bet that dates me...).

[jdsmeak]

I have two of the Everspring ST814-2 temperature and humidity monitors. How do you get it to display humidity or temperature as its primary read-out on Mobilinc, or in programs? Teken, do you have any experience here that you can share? Thank you!

[MWoods329]

I have two of the Everspring ST814-2 temperature and humidity monitors. How do you get it to display humidity or temperature as its primary read-out on Mobilinc, or in programs? Teken, do you have any experience here that you can share? Thank you!

I have the same device. Works well for me.

Didn't have to do anything to it.

 

Sent from my iPhone using Tapatalk

[jdsmeak]

The issue for me is that it displays as you have it, but I want to display temperature instead of humidity... Any luck there?

 

 

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[MWoods329]

The issue for me is that it displays as you have it, but I want to display temperature instead of humidity... Any luck there?

 

 

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Ah... I understand your frustration now.

No, I wanted it to display humidity and never really looked into displaying the temperature.

 

 

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[Teken]

I have two of the Everspring ST814-2 temperature and humidity monitors. How do you get it to display humidity or temperature as its primary read-out on Mobilinc, or in programs? Teken, do you have any experience here that you can share? Thank you!

 

Hello Jdsmeak,

 

I don't have or use the Everspring ST814-2 in my home automation set up to monitor humidity in my home. I have six Venstar TSTAT's that were calibrated using the salt validation method to measure and track RH.

 

My Autelis Bridge is also wired to a Hobby Board 1 Wire Honeywell humidity sensor which also pumps its data to the ISY Series Controller for conditional logic, venting, and air management in the home.

 

In the future my outdoor weather station will correlate the inside vs the outside for more micro climate control. My goal is similar to MWareman where I would like compare the two and act upon the immediate climate.

 

Keep us all in the loop as to how you resolve this issue . . .