Z-wave thermometer?

[Robthedog]

Hi. WOW this Z-Wave thing is so sweet, just discovered it this week. :-)

OK, please help a newbe out as I got stuck before I've even begun. There is one thing that I don't get...

I have a simple cabin in the woods in a Nordic country. It does, however have both electricity and a DSL connection, and that makes Vera perfect for me. The cabin is heated with 1 electrical radiator per room (like this one: bit.ly/z07TJz ). What I want to do with Vera / Z-Wave is to keep the radiator heating in the rooms on a low "ecomode" while away and then remotely pre-heat the cabin for when we go there.

What the system needs to do: turn on 1 electrical radiator per room when the temperature in the room drops below x and turn it off when the temperature reaches y. Temperatures defined in Vera.

For this I guess I need:
* 1 Vera2
* 1 on/off switch per radiator (like this bit.ly/AzI5hs )
* 1 Z-wave enabled thermometer per room

Now this is what I cant find. I mean, there are all sorts of fancy Thermostats capable of controlling complex HVAC-systems with touchscreens and whatnot, usually over 100$ a piece. But where can I find a simple inexpensive (preferably battery driven) Z-wave thermometer or temperature sensor, which basically just reports the current temperature to Vera, where I will define triggers?

So how would you set this one up? I'm curious to see if I'm just thinking something wrong in my setup?


PS. I know about the HSM100 ( bit.ly/yYeBfA ), it just seems a bit overkill for my basic needs.

[intveltr]

Z-wave sensors do indeed seem a little pricey, especially, if you need several.  Also, even though Z-wave thermometers often have a resolution of 0.1 degree or better, Vera only captures and stores the temperature in whole degrees.

Have a look here: http://forum.micasaverde.com/index.php/topic,8926.msg58159.html#msg58159   There's an alternative solution based on the "1-wire" link, employing cheap temp sensors, and use some software/hardware to interface it to Vera and control heating.   You'll probably have to run some (thin) wiring for the sensors but depending on how many rooms you need to control, it may work out to be a whole lot cheaper.  They also give you a better resolution.

[dreamgreenhouse]

I too can't believe there are no thermometers available. I'm after a simple, powered (so it can act as a Z-Wave relay, 12Vdc ideally) wall mounted thermometer that I can put on the wall in every room. I'd like it to have be about 50mm in diameter, with a nice OLED display showing the current temperature. It needs to be more stylish than the NEST thermostat :-)

I'm going to see if I can get a device designed and built in volume for me, as I think this is huge gap in the market. If Fibaro can get all those electronics into their devices, then it has to possible to make and sell at a reasonable price. If anyone gets there before me, then so be it.

Rob

[pncarrerars]

How about http://www.vesternet.com/z-wave/thermostats-blinds/z-wave-everspring-temperature-and-humidity-sensor-p-1058.html I have used one for a while and it seems to work fine.

[dreamgreenhouse]

I've got one of those. It's too big and ugly and battery powered.

[Chris]

It's not a z-wave solution, but you could look at the EDS One-Wire sensors (http://www.embeddeddatasystems.com/OW-ENV--Environmental-Sensors_p_172.html). These do need wiring to a server (3 wires required - data, ground and power) and can come with a relay.

I've written a plugin for the EDS One-Wire Server to interface to these. The other advantage is that the sensors then report with a resolution of 0.1deg, where the Z-Wave ones only present 1deg resolution (not because of the sensor, but because of the way Vera processes the data). See http://code.mios.com/trac/mios_ow-server.

Chris

[pncarrerars]

I've got one of those. It's too big and ugly and battery powered.

The original poster wants a battery powered one. In my opinion it is small and not ugly plus the battery lasts almost a year

[scherbs]

If you are looking for something to simply report temperature I wonder if you could just use a freeze alarm like the fortrez  http://shop.micasaverde.com/index.php/sensors/fortrezz-wwa-01-z-wave-wireless-water-and-freeze-alarm.html

I have one and it reports temp accurately and is small and can be placed in a cupboard or closet on a shelf so you would not have to see it all the time.

[Massfeller]

It's been a year has anyone come up with a better solution, Rob did you ever get your project off the ground? The design sounds promising.

[raviouze]

Hello, I also search for a Z-wave simple low cost temperature sensor, less than 20$. I need to put at minimum 3 or 4 sensors in different position of the house... so the cost is important... I just spent many hours on internet and don't find... need help !

[mikee123]

I use Oregon Scientific sensors. They are not zwave but i can pick them up through my Rfxtrx, and i use them in scenes and PLEG to control my heating/AC, and they report a usable 0.1 degree resolution and are not that expensive. Obviously if you have to buy the Rfxtrx first and only need 3 or 4 it might not be worth it, but if you need more and or have it anyway worth looking into.

[toxick]

Was just looking for a solution and came across this thread.  Reviews on this says it works with vera:

http://www.smarthome.com/65456/Everspring-ST814-Z-Wave-Temperature-Humidity-Sensor/p.aspx

[parkerc]

I just wanted to add to this thread the option of the Fibaro Universal Sensor (http://www.fibaro.com/manuals/en/FGBS321-Universal-Sensor/FGBS321-Universal-Sensor-en-2.1-2.3.pdf)

As a z-wave device you have the ability to run 4 individual temperature sensors off of it.

[curiousB]

This is a bad idea. You shouldn't use Vera as a control element in a closed loop heating scheme. It adds complexity and has suspect fail safe reliability.

Instead use a 24VAC set back thermostat with ZWave (or WiFi) control. That way the thermostat is in the closed loop control element and Vera is just modifying set points and operating modes. The heating system operates independent of WAN connectivity, Vera crashes, and so on. You can use an electronic thermostat with a 24VAC relay for line powered baseboard heat.


http://www.smarthome.com/300612T/Aube-RC840T-240-On-Off-Switching-Electric-Heating-Relay-with-Built-in-24-V-Transformer/p.aspx

http://store.homeseer.com/store/2GIG-CT100-Z-Wave-Programmable-Thermostat-P1324.aspx?gclid=CKLjrdiCpLwCFUpk7AodSwQAqw

[Bagheera223]

I totally agree with curiousB - this is the way to go.   I have a house that was passed on to me in 2006 and until last year I wasn't living in it so needed to be able to monitor the temp and also control it.  So I installed a vera 2 and a Trane thermostat and it works the baseboard heat which is run by a boiler furnace in the garage.   So I can monitor, and control interactively or I can set up patterns as needed.   I did run into a situation where in extreme cold a pipe that was next to an uninsulated wall burst while I was visiting a friend and I was able to let my neighbor in via the control I have of garage door plus the Schlage lock on front door.    So I added a sensor for temp & water leak in the garage and I also installed a heat lamp that I can control via a smartswitch via Vera.   For now I'm having some connection issues with the Fortrezz water/temp remote sensor, but when I get that solid I can set up a relationship where the heat lamp comes on when temp drops below a level (I'm living here now but if I have to move away for a job this will be better than me constantly monitoring.