SmartThings Community

Good Sensor to monitor unoccupied 2nd Home temperature?

I would like to utilize a sensor that will alert me when a room reaches a temperature of my choosing.
Can the multi purpose sensor do this? If so, which sensor would that be?
Thank you in advance.

Different models have different features. By definition a “multi sensor” can report on more than one environmental factor, but again, different ones report on different things.

The SmartThings brand multisensor is very unusual in that it combines a open/close contact sensor with a thermometer. There are other multi sensors which Might be able to report motion and temperature, or light level and temperature, etc.

So there are two questions: exactly what do you want reported from the single device and then how accurate does it have to be.

Many of the multi sensors to report temperature, but they aren’t very accurate. It’s common for them to be plus or minus 2° some of them are plus or minus 5°. That might be fine for something like closing a water valve if a freeze was expected, but it wouldn’t usually work for Adjusting room temperature for healing and comfort. There’s a big difference between 66° and 71° for that use case.

It also probably wouldn’t work if you were trying to maintain temperatures for a grow room or an aviary adjusting room temperature for healing and comfort. There’s a big difference between 66° and 71° for that use case.

It also probably wouldn’t work if you were trying to maintain temperatures for a grow room or aviary am. .

But there are other sensor specifically meant to act along with the thermostat that have much better accuracy, anywhere from plus -1° to even plus -0.25°. But the more accurate ones generally cost more.

So, let’s start at the beginning. What environmental factors do you want the sensor to be able to report? And how accurate does it have to be on temperature.

Typical sensor reports might be

M but there are other sensors specifically meant to act along with the thermostat that have much better accuracy, anywhere from plus -1° to even plus -0.25°. But the more accurate ones generally cost more.

So, let’s start at the beginning. What environmental factors do you want the sensor to be able to report? And how accurate does it have to be on temperature.

Typical sensor reports might be:

motion near the sensor
Motion of the sensor (open/close sensor or accelerometer)
Vibration
Light level
Humidity
Leak or flood
Smoke
Carbon Monoxide
VOC
Air pressure
Angle of sensor, usually called a tilt sensor
Sound levels
Pressure/force applied to sensor

And I’m sure there are some more I’ve forgotten. :sunglasses:

So what do you want to get reports on, and again, how accurate do the reports need to be?

Oh, and I forgot… Most multi sensors only report temperature every 15 minutes. Again, that will work fine for some situations, but not for others.

Not directly. You can do that through Webcore/Lanouncer on your phone/tablet. Otherwise it’s more complex.

Thank you so much for your great info and the great questions that I need to answer.

So, for right now I need 2sensors that will notify me by email or text when the temp reaches a level set by me and I would like accuracy. It does not need to trigger any action by any other device.
This is for a home in South Florida that will be unoccupied for months at a time.
I want to protect against mold growth. I want to be alerted if the HVAC system is not operating
correctly.

Since you posed the question,
I may need smoke and carbon monoxide sensors as well as I do not yet know whether those sensors already in the home are tied into the existing alarm system’

A recommendation for water sensor is also appreciated.

Thank you again for your informative response.

How much accuracy do you need? For temperature sensors this is expressed as a plus/minus.

For example, a sensor with a plus/minus of 2° might be inaccurate by that much. So it might report the temperature is 70° when it was actually 68° or 72° or anywhere in between.

A different sensor with an accuracy of plus/minus 1° might be inaccurate by that much. So it might report a temperature as 70° when it was actually 69° or 71° or anywhere in between.

And one of the more expensive sensors has a plus/minus of 0.2°. So it might report the temperature as 70° when it was actually 69.8 or 70.2 or anywhere in between.

For your purposes I would think a plus/minus of 2° should be fine. But obviously that’s up to you.

I’m going to retitle this thread so hopefully you’ll get more people responding.

Do you already have a SmartThings Hub For this location? And if so, which model? Otherwise were you intending to use Wi-Fi sensors, because there aren’t very many of those available.

Finally, before we go too much further… Is there someone available near the house who can go over if there are any issues. Smart things does have fairly frequent outages, historically typically at least one a month for the last 20 months. The outages may last only a few minutes or if you happen to be one of the unlucky few runs into a problem it could be a day or more.

In particular, it is quite common that after a Hub firmware update, which typically comes about once a month but sometimes more often, that some of your sensors might have to be physically reset, that is the case opened, the battery removed, and then replaced. So you might need to have someone go over and do that.

You can see a discussion of issues some people are having after the most recent update in the following thread. Again, this is an everybody every time, but it is an issue to be aware of in planning.

And here’s a discussion on planning for outages:

Thank you so much for your response.
I do have a V2 at my home up north. I will order a new hub for my Florida home. I was planning on a V3 for Florida but when I sell my home up north I can swap them. Physically resetting the sensors is not something that I will be able to accomplish without training a new neighbor so I prefer a sensor that will not necessarily require a reset. As far as sensitivity is concerned +/- 0.2 is preferred but +/- 2 will suffice if the sensors are less likely to need a reset.
Please explain what you mentioned about needing wi-fi sensors as I would prefer to have a larger selection of hardware. I have no problem with ordering a V2 instead of a V3 as I think that that placing the hub near the router will not cause any problems and thanks to youtube, I am able to terminate ethernet cable.

If you weren’t going to use a hub at all, you could use Wi-Fi sensors and the new app. There aren’t many manufacturers who make these, but there are some.

The battery operated ones have very short battery life when compared to zigbee or zwave, as little as 2 months, so they won’t meet your requirements.

There are a couple of plug-in ones, but they do tend to be more expensive than the zigbee or zwave ones as well. But if you have a good strong Wi-Fi they might be more reliable in the sense that they won’t be as likely to be affected by the smartthings cloud. You do have to experiment to see if they stay connected, some people find that a particular model is better than another.

If you want more information we can discuss some specifics.

What is your HVAC system like? The one that you want to make sure is operating? Is it individual AC units or do you have a central thermostat?

If you do have a central thermostat, the easiest thing might be just to put in an ecobee and some of its remote sensors And get your notifications that way.

Once you have the sensors in place you can setup a simple notification from the new or old apps. You don’t need webcore or any other system for a simple notification. There are two sample apps in the IDE called “It is to cold” or “It is to Hot” that will also do notifications and allow you to turn on a switch for heating or cooling if needed.

I would suggest you set it up the notification and any action taken in the new app though.

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You ask perceptive questions. That is a good thing, you are a good teacher.

If you weren’t going to use a hub at all, you could use Wi-Fi sensors and the new app. There aren’t many manufacturers who make these, but there are some.<<

I do want to use a hub so would want to stay with zigbee/zwave.

What is your HVAC system like? The one that you want to make sure is operating? Is it individual AC units or do you have a central thermostat?<<

2 separate HVAC systems and Tstats. One of them is a smart unit. but I do not know whether it is zwave or wifi. Up north, I have 2gig Tstats that I communicate with via my ST app. When I return to Florida next fall I will bring my 2gig Tstats with me and will not need the temp sensors that I plan to purchase now. So, for right now I need to decide on which version hub and which temp sensor. Reliability is important.

again…
Thank you so much for your time.
Danny

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dan,

I am monitoring our unoccupied second home in the exact opposite climate - outside of west yellowstone. My concerns are with temperature, but I would suggest that your concerns in florida should be humidity and secondarily temperature. My mom’s condo in florida has had issues with mold when unoccupied, so depending on your HVAC setup, you can have have issues with mold that are related to humidity - which may or may not be temperature related. I have dealt with mold issues in her condo, and understand your concerns.

There are a few multi sensors that monitor humidity - Zooz 4 in one - I have two of these, they seem to work well so far - but I can not verify accuracy. But you can configure these to alert you of changes in any of the monitored parameters. I believe there are others - Aeon off the top of my head.

A couple thoughts regarding accuracy and reliability. One, the reliability IMHO is improved with a robust mesh network, so multiple repeaters are a must. The ability to control the hub, ie power cycle, turn on/off to reset the zigbee mesh I addressed by adding a wifi outlet and plugging the hub into that outlet. Battery operated sensors - I used multiple different types, zwave and zigbee, multisensors from multiple vendors and leak sensors (with temp monitoring). I used multiple different types of sensors for a couple of different reasons, questions about accuracy etc, battery life, and I thought I could also monitor “activity” (motion) and temperature.

Finally, one thought regarding accuracy, one suggestion I would propose is you get a webcam (I am happy with my EZVIZ) and purchase an accurate device ie Lacrosse or some other thermometer that has humidity and place the webcam appropriately so that you can view that device with a wifi webcam. There are zillions of webcams and they are relatively inexpensive.

I do not have the confidence in a zwave/zigbee controlled HVAC system, I would stick with the more established wifi versions at this point in time.

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Great info Madisonriver. Thank you.

I will add what I learned from my experiences with mold in my mom’s condo (which had zero monitoring except and 85 yo full time resident neighbor who would “check” the residence periodically).

One is power outages, a hurricane can cause prolonged power outages, and your will monitoring will be out during the power outages, along with your HVAC. So if you do not have a power backup for you HVAC - you are primed to get mold. Insurance coverage for mold is limited - so budget accordingly - or thoroughly vet your insurance coverage.

IMHO, I think mutliple multisensors with humidity, a couple leak sensors (placed under windows or areas prone to prevailing wind driven rain) with alerts easily configured with smart home monitor would be the first line of defense. A webcam as described above would be well worth the cost with a really accurate humidity reporting would be the second line of defense. An up to date HVAC that has a dehumidifier as well as air conditioning. And finally, do not attempt to save a few bucks, you have to run that HVAC system agressively or risk losing all of you furniture, carpeting and expose yourself to rather expensive mold mitigation costs. Find a neighbor who knows what mold looks like and the conditions that allow mold, and pay them to keep a constant vigil on your investment.

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Excellent advice. Thank you.

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I would make it a redundant setup, no matter what you purchase. A video feed would be nice also.