Trigger on difference between temperature of two probes

[mcbeath]

I’m looking for a way to trigger an event when the difference between two different temperature sensors exceeds some threshold … without having to write scripts or code. Is that possible with HS3? I don’t own a HomeSeer hub, but am considering buying one for this use; hopefully something not too expensive, like maybe the a HomeSeer HomeTroller Zee S2.

For the temperature probes, I’ve been looking at Ambient Weather, such as their WS-0265, WS-8482, WS-2801A, or WS-50-C. Does the Simplex/Ambient Weather plug-in for HomeSeer support any or all of those models?

Here’s more about the specific application we’re considering: we have an uncooled space where our big freezer is. We only go in there occasionally (maybe once or twice a day). We use fans in the windows, bringing in air from the outside, to keep the space from overheating and have been just been manually monitoring the temperature (not using thermometers, just how hot it feels), turning it on when it seems like it is probably cooler outside than inside. Basically, we often just turn it on and leave it running all day or all night … not very efficient.
It would be great if we could put the fans on a smart outlet and setup a rule to do this more automatically, with one temperature sensor inside and one temp sensor outside. The rule would be something like “If the temperature from the inside thermometer becomes more than 5° above the temperature from the outside thermometer, then turn on the fan” and a second rule that says “If the temperature inside becomes less than 3° warmer than the temperature outside, then turn off the fan”. I would expect we would experiment with the actual values of those differences, to get the hysteresis value correct.
Any advice on the best way to do this would be welcomed. By ‘best’ – I mean least amount of work, while still being an economical solution. I’m willing to spend a bit more to save time and effort making it work, but still it is not worth spending hundreds of dollars on this project.

Thanks.

[simplextech]

I’m looking for a way to trigger an event when the difference between two different temperature sensors exceeds some threshold … without having to write scripts or code. Is that possible with HS3? I don’t own a HomeSeer hub, but am considering buying one for this use; hopefully something not too expensive, like maybe the a HomeSeer HomeTroller Zee S2.

A Zee S2 would be a nice little unit for a lot of things.

For the temperature probes, I’ve been looking at Ambient Weather, such as their WS-0265, WS-8482, WS-2801A, or WS-50-C. Does the Simplex/Ambient Weather plug-in for HomeSeer support any or all of those models?

The WS-8482 is verified and functions well. I personally own/use one. The WS-0265 and WS-50-C are not tested but should work requiring only minor plugin updates if any at all. The WS-2801A will not work as it does not send data to AmbientWeather.net

Something to note about those units is they are cloud dependent so they will send the temperature data to AmbientWeather.Net and the plugin will then pull that data back to be used in events. If there is an internet problem then data won't be available.

It would be great if we could put the fans on a smart outlet and setup a rule to do this more automatically, with one temperature sensor inside and one temp sensor outside. The rule would be something like “If the temperature from the inside thermometer becomes more than 5° above the temperature from the outside thermometer, then turn on the fan” and a second rule that says “If the temperature inside becomes less than 3° warmer than the temperature outside, then turn off the fan”. I would expect we would experiment with the actual values of those differences, to get the hysteresis value correct.
Any advice on the best way to do this would be welcomed.

Yes this type of event is quite easy to do with HS3 and the plugin. You will have to have a smart plug to do this. For a fan use it should be rated amp wise to handle it. The Zooz ZEN15 is a good choice and economical.

By ‘best’ – I mean least amount of work, while still being an economical solution. I’m willing to spend a bit more to save time and effort making it work, but still it is not worth spending hundreds of dollars on this project.

Thanks.

Best and Cheap don't usually go together. The above outlined system will work but it is not the cheapest route when you add in the Zee S2, the Ambient Weather station and the temperature sensors then not just one but several power plugs to form a z-wave mesh to reach the Zee S2. You could get by with only one plug if the Zee S2 is in close proximity.

Something else to be aware of is that I'm currently working on a plugin for EcoWitt. Their gateway is very inexpensive and supports the sensors like Ambient Weather sells (it's the same hardware from the same vendor) The EcoWitt GW1000 does have local data push capability which will remove the cloud/internet dependency. This new EcoWitt plugin will be released in the next couple of weeks (maybe sooner).

[cc4005]

I’m looking for a way to trigger an event when the difference between two different temperature sensors exceeds some threshold … without having to write scripts or code. Is that possible with HS3? I don’t own a HomeSeer hub, but am considering buying one for this use; hopefully something not too expensive, like maybe the a HomeSeer HomeTroller Zee S2.

For the temperature probes, I’ve been looking at Ambient Weather, such as their WS-0265, WS-8482, WS-2801A, or WS-50-C. Does the Simplex/Ambient Weather plug-in for HomeSeer support any or all of those models?

Here’s more about the specific application we’re considering: we have an uncooled space where our big freezer is. We only go in there occasionally (maybe once or twice a day). We use fans in the windows, bringing in air from the outside, to keep the space from overheating and have been just been manually monitoring the temperature (not using thermometers, just how hot it feels), turning it on when it seems like it is probably cooler outside than inside. Basically, we often just turn it on and leave it running all day or all night … not very efficient.
It would be great if we could put the fans on a smart outlet and setup a rule to do this more automatically, with one temperature sensor inside and one temp sensor outside. The rule would be something like “If the temperature from the inside thermometer becomes more than 5° above the temperature from the outside thermometer, then turn on the fan” and a second rule that says “If the temperature inside becomes less than 3° warmer than the temperature outside, then turn off the fan”. I would expect we would experiment with the actual values of those differences, to get the hysteresis value correct.
Any advice on the best way to do this would be welcomed. By ‘best’ – I mean least amount of work, while still being an economical solution. I’m willing to spend a bit more to save time and effort making it work, but still it is not worth spending hundreds of dollars on this project.

Thanks.

I've just done something very similar in my garage, comparing inside and outside temperatures. I use the EasyTrigger plugin to compare the values of the 2 devices. I'm using 1-wire temperature probes connected to an EDS 1-wire server device on my LAN, interfaced with HS3 via the Ultra1Wire3 plugin. The Ambient Weather sensor solution may be just as economical for your purposes--I'm not familiar with its cost. The 1-wire setup and both plugins I'm using are additional cost, but each provides substantial other functionality to my system beyond this application.

EasyTrigger let's you compare devices 2 devices (with + or - offset) or trigger on evaluation of an expression...among many other uses.

[mcbeath]

The WS-8482 is verified and functions well. I personally own/use one.

Well, then I'm tempted to go with that, since you are likely to keep supporting it well :-)

Something else to be aware of is that I'm currently working on a plugin for EcoWitt. Their gateway is very inexpensive and supports the sensors like Ambient Weather sells (it's the same hardware from the same vendor) The EcoWitt GW1000 does have local data push capability which will remove the cloud/internet dependency. This new EcoWitt plugin will be released in the next couple of weeks (maybe sooner).

Not sure I want to be the first to try out new code, but the local data capability might swing me in this direction. I guess I'll wait to see if/when you release it.

[simplextech]

Well, then I'm tempted to go with that, since you are likely to keep supporting it well :-)


Not sure I want to be the first to try out new code, but the local data capability might swing me in this direction. I guess I'll wait to see if/when you release it.

The WS-8482 is good for just little sensors. I also have the WS-1401, WS-2902 and the EcoWitt GW1000 in the mail... So the EcoWitt plugin should be coming soon as long as there isn't any major issues with it. The local data functionality of the GW1000 has been wanted by many for a long time.

[AshaiRey]

Without reading all i would say have a look at the DeviceCompare plugin

[mcbeath]

Without reading all i would say have a look at the DeviceCompare plugin

AshaiRey, Do you know if DeviceCompare would be better (easier to setup, more reliable) than the Easy Trigger plugin for my purpose? I need to be able to easily include an offset (i.e. 'difference') value in the trigger - like temperature A is < temperature B + 5°. Looks pretty straightforward with Easy Trigger.

[ericg]

AshaiRey, Do you know if DeviceCompare would be better (easier to setup, more reliable) than the Easy Trigger plugin for my purpose? I need to be able to easily include an offset (i.e. 'difference') value in the trigger - like temperature A is < temperature B + 5°. Looks pretty straightforward with Easy Trigger.

It is easy with Easy Trigger. If you have this plug-in, you will have no difficulty comparing the temperatures. If you don't have it, I strongly recommend that you get it. I use it almost daily for all kinds of things.

[mcbeath]

It is easy with Easy Trigger. If you have this plug-in, you will have no difficulty comparing the temperatures. If you don't have it, I strongly recommend that you get it. I use it almost daily for all kinds of things.

Great - thanks.