Attic sensor that can handle 0° to 150°F?

I have a ST Zwave hub with several devices connected. My goal now is to connect a temp sensor to my attic fan and use the temp to control the fan (on/off). The only one I can find with sufficient temp range is the Sonoff temp switch. Which leads me to a few questions.
It appears the cord length is 3’. I’d like 6-8’. Is there a longer cable I can buy/attach?
I suspect there are other sensors with a wide enough temp range. Guidance please.
I’m guessing the ‘device’ will not survive high temps and must be placed inside the house, thus the longer cord. Is that correct?

There’s no such thing as a Samsung SmartThings ™ “Z wave hub.” All of the SmartThings hubs are multiprotocol, containing at a minimum Z wave and zigbee. This is relevant to your question because many of the best sensors are zigbee, not Z wave. Did you only want to consider Z wave sensors or are you also open to Zigbee?

Also, what country are you in? The device selection does vary somewhat.

And finally, what’s the specific range of temperatures that you are looking for?

Thanks for the quick reply. I thought z-wave only talked to Z-wave. Apparently not true. No, I’m not obsessed with Z-wave.
I’m in the USA.
The Sonoff range is -55 to 125 deg c. I’m guessing I want 0 deg to 150 deg F. I’m ~38 deg latitude

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It is true that the zwave communicates only to Z wave but the point of a multiprotocol hub like smartthings is that the hub itself can talk to devices of multiple protocols. So it’s very common, for example, in a smartthings setup to have a rule where when a zigbee sensor tells the hub That motion has been detected, the hub will tell a zwave light switch to turn on.

Technically, the Zigbee sensor isn’t talking to the Z wave light switch, but since the hub can talk to both, the end result is the same. :sunglasses:

So that broadens my options. Any suggestions?

I have an aqara temp/humidity sensor in the attic. I’ve seen it get to 130 and never have an issue.

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Check the exact specs, some of these might only go up to 140° and I don’t know if that works for you.

  1. The Aqara are definitely popular for a budget sensor. They use zigbee, so depending on the distance from the hub you might also need a ZIgbee repeater. The IKEA Tradfri plug-in pocket socket only cost $10 when bought directly from IKEA and is a very good zigbee repeater
  1. A more expensive option, but Z wave plus (so longer range) and really well engineered is the Sensative Comfort strip. Does temperature and light, not humidity.

I use an ecosmart bulb from Home Depot up in the attic to act as a repeater for this specific aqara sensor. All my other aqara sensors route through IKEA plugs and I have no drops. Both are very cheap and reliable routers.

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Thanks for all the replies. A few followups. Is it correct buying the Aqara sensor requires buying a hub?
The sensor will be !25’ from the router through one ceiling. I shouldn’t need a repeater.
I’d much prefer a sensor that plug in to AC. There is an outlet about 2’ away from where the sensor will be. So far, haven’t found one.
What happens if the ambient temp exceeds the range of the sensor? Is the sensor damaged or just doesn’t report the temp?
No one has mentioned the Sonoff? Should I read anything in to that?

The Aqara sensor connects directly to your smartthings hub. You do not need their gateway as well, it’s one or the other.

If you exceed the operating range, the sensor itself might be damaged.

For plug ins:

  1. Homeseer HSM200. Operating range -4°F to 176
  1. Aeotec multisensor 6. Operating range 14°F to 122°. Can be mains powered via a USB cable. May be able to handle higher heat if it doesn’t have batteries: check with the manufacturer.
  1. zigbee Device manufactured by a community member, Quantities limited. I don’t know the operating range, you would need to check with the creator.

There are a few others, but I think those are the most popular.

I can’t say anything one way or the other about the sonoff. The brand is generally good, I just haven’t heard anything about that particular device.

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I have two Aeoteks I use under my house to monitor temp (risk of freezing water pipes). work very well, but, yeah, temp range is a little tight on the high end. I’ll contact Aeotek and range on AC.
Just a quick search of the sensors mentioned shows most may work. I’ll do a more detailed view when I get time.
I was hoping for one with a long temp probe so I could mount one in the living area and run the probe to the attic. Less risk of damage to the base (I hope).

If you want to use a probe, that’s another option. You can get any standard DS18B20 probe and connect it to a Z wave device that will report to smartthings. See the following discussion

That said, probes are usually terrible at reporting plain old ambient air temperature. They really work best when they are either submerged in ground or liquid or taped to a pipe. So you can try it, but I’m not optimistic for this particular use case.

Hey, I just want to let you know that I make Zigbee Sensors. The sensor is expandable. The latest expansion is that you can connect an arduino and use temperature probe. You can look at this picture. Please skip to post 400. I use a temperature probe DS18B20. DS18B20 can cover the range that you mentioned. I use Ethernet cable to extend the probe. I feel that I can push the cable longer with Ethernet cable but I never try it.

I think this solution is used by a member here to measure the temperature of a lake behind his house.

I will be happy to help if you need help. Please feel free to send me a PM.