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scott_araujo

External Temperature Sensor vs. Wifi

6 years ago

I just had a new Lennox heat pump system installed along with an iConfort M30 smart thermostat. The contractor did not realize the external temperature sensor was not included so said he will get one and install it shortly. I noticed you can also simply connect the thermostat to wifi and use wifi to get your local external temperature. Do I still need the external sensor? Is there an advantage of an external sensor over wifi?


Thanks,

Scott

Comments (25)

  • 6 years ago

    The purpose of the external temperature sensor is to inform the HVAC system the status of the outdoor temperature. If you have a multi-stage system, the thermostat should decide how long and what stage it should operate in based on the indoor and outdoor temperature. I am not familiar with the Lennox thermostat algorithms so I don't know if your thermostat will actually do this. Ask your contractor when he comes back to install the sensor.

    You can see the outdoor temperature with the WiFI connection, but I doubt the thermostat's software is able to extract the temperature information. If it could then the outdoor sensor would not be needed.

    scott araujo thanked mike_home
  • 6 years ago
    last modified: 6 years ago

    My thermostat displays outside temperature via a sensor mounted outside. At a minimum it uses it to determine when to go to oil heat from my heatpump and vice versa. (Believe the term is "Crossover Temp.")

    scott araujo thanked Stax
  • 6 years ago

    I figure it uses the outside temp to determine how long to run, etc. but I hadn’t considered that it may use the WiFi data for display only. That’s a good point that it may display it but not feed that into the algorithm.

  • 6 years ago

    Your manual says:

    Outdoor Temperature Display

    >>

    Off

    >>

    Internet (requires Internet connection)

    >>

    Sensor (requires that an outdoor air temperature sensor is installed and enabled under Advanced Settings > Outdoor Sensor).


    I would emphasize that it says DISPLAY. Maybe it also provides temp data for control????


  • PRO
    6 years ago
    last modified: 6 years ago

    IMO, WIFI is not a good idea. These networks are often times compromised then gateways into your homes network.

    Plenty of examples of Nest door bells being compromised among other things. If your desire is to connect to the internet it is much better to use a dedicated connection and not WIFI.

    A signal from a mounted out door sensor is more accurate than data collected from some other local point. This probably won't vary much, but a mounted signal on the equipment is also much more reliable.


  • 6 years ago
    last modified: 6 years ago

    You're concerned about someone getting into your home's WiFi and messing with your heating and cooling? lol sheesh.

    Also, who cares if the outside sensor differs by a couple of degrees from that at, say, the local Post Office. My outside temperature indication goes up a few degrees when it is defrosting and varies a degree or two if the wind shifts briefly.

  • PRO
    6 years ago
    last modified: 6 years ago

    You're concerned about someone getting into your home's WiFi and messing with your heating and cooling? lol sheesh.

    Nope, they use it as a 'back door' to gain access to the home network.

    If you have one unsecure IoT of things how likely are you to have multiples of these.

    Think cameras... nanny cams or security cameras.

    The thought goes: If someone has cameras, security devices -- there must be something of value there.

    They then use those cameras that are also on the WIFI of the home network. Those cameras are then used against the home owner to track movements of the occupants.

    The statistics posted above tell a story... not a good one.


    Remember --- this is all about having fun. You choose how much fun you want to have.


    ---------------------------------

    Nice try Mike --- but no.

    What happens if I hide my SSID?

    If an SSID is hidden via the network setup page, the name typically becomes null. ... For hidden networks, the SSID name is missing from beacon frames but included in Probe Response frames. Hiding an SSID does not provide true security because it only hides the network's name and not the actual network.Apr 9, 2018

  • 6 years ago

    I agree with what you posted. You should always use strong passwords and with an encrypted network. Hiding the SSID is another layer of protection but should never be the only layer. The hack has to first figure out the name of the network and then figure out the password. If your devices use WPA2 encryption then you should be safe.

    I am not familiar if Nest and Ring doorbells offer dual authentication. If they do then that should be enabled.


  • 6 years ago
    last modified: 6 years ago

    So, if I have a WiFi network at home with say a dozen items on that network, is it is your contention that I am at higher risk of being hacked if I am connected to the thermostat manufacture's server with an encrypted system and a PIIN and Password?

  • PRO
    6 years ago

    Stax,

    If you use a WIFI network at all in your home, your home network can be hacked. It doesn't have to be HVAC....


    Watch the video:



  • 6 years ago
    last modified: 6 years ago

    " If you use a WIFI network at all in your home, your home network can be hacked. It doesn't have to be HVAC.... "

    I know. What I asked you was, " is it is your contention that I am at higher risk of being hacked if I am connected to the thermostat?" (In addition to the other ten+ WiFi Devices I have connected.)

  • 6 years ago
    last modified: 6 years ago

    BTW, the video you posted should not be available on a heating forum, in my opinion. That, of course, is just my opinion.

  • 6 years ago

    Good video demonstrating why you should not use a weak WiFi network password. It would have been nice if the weak password was stated in the video.

  • 6 years ago
    last modified: 6 years ago

    I recently got an email from Experian touting their much-advertised credit "Boost" program. I went to their website and in order to possibly increase my credit score (it's already 830) they wanted my bill pay bank account number and password (remember, they were hacked 2 years ago and millions of peoples private information was stolen)! Needless to say, I'll pass on their gracious offer!

    If your third party weather reporting service (probably Accuweather for Honeywell) get's hacked, they can obtain any information you provided when setting up your app account in addition to your ISP, your IP address and possibly access to your network/computer (do you bank online?)

    In any event, I'd rather have an external sensor that a ZIP code average. Precautions can be taken to position the sensor where it won't get anomalous results.

  • PRO
    6 years ago

    I know. What I asked you was, " is it is your contention that I am at higher risk of being hacked if I am connected to the thermostat?" (In addition to the other ten+ WiFi Devices I have connected.)


    All it takes is one device... it doesn't matter what kind. HVAC is often not thought of as a security risk which more often than not leads to an easy access point to the home network.

    If a lock can be built, it can be defeated. WIFI is inherently weak in terms of security. The video posted above is a 'beginner' type way to do it. It leaves evidence of who attacked... The video is merely to show you it can be done.

    Any lock can be defeated. How many data breaches have we seen over the past several years? Banks and so on... you think those passwords were weak?

    I would never consider using WIFI. For anything, because it makes you extremely vulnerable. But that's me, you can do whatever you want.

  • 6 years ago

    "I would never consider using WIFI. For anything, because it makes you extremely vulnerable."

    Wow!

  • 6 years ago

    "Banks and so on... you think those passwords were weak?"

    Quite possibly, even so-called professionals may not enforce strong passwords.

    Or an employee may (stupidly) respond to a phishing email. Happened to city offices in a nearby town. Many of the city office computers and some connected services such as police and EMS were infected by file key-encryption malware. They had to wipe-out and restore software and data backups, rebuild some of the data.

  • 6 years ago

    Thermistors are cheap. I spent maybe $30-50 in parts and an hour or so to hook up. Running the wire too the longest.

  • 6 years ago
    last modified: 6 years ago

    And weren't you fortunate that the thermistor you found had the correct ohms per degree response slope and the resistance of the leads from the outside device to the thermostat's interior location so that the thermostat display and the furnace control circuitry responded correctly?

    Why, it's an absolute miracle.

  • 6 years ago

    I knew it was a 10K type II (fortunately the Carrier manual provided the info). Of course one needs to know the specs. The Carrier unit (acquired cheap from someone who went to a smart thermostat) does all the controlling. The heat pump and air handler are rather dumb (just single stage/speed)

  • 5 years ago
    last modified: 5 years ago

    Thank you for sharing your experience, I don't know if I should install external sensors yet. To update my post, I want to say that I decided to install external sensors, because after studying this issue, I realized that this is the right decision. Moreover, I talked to a specialist and he told me the same thing. By the way, during the search, I came across an article about water temperature sensors and I have a question for you. If you use this device, please share your experience. I read that this is a very important thing to monitor water quality. Actually, I understand that, but I want to get live reviews.

  • 5 years ago
    last modified: 5 years ago

    Plagiarism again. Additionally, the case in this thread is seven months old and the above plagiarism is not on-topic.

    Interesting the poster is the one that "Liked" his own post. I believe it is a bot or bot/human post.

  • 5 years ago

    I am assuming by WiFi, you mean connecting to the internet to get the outside temperature. Remember, the network connection will fail periodically, so I would definitely use a hard-wired outside temperature measuring device (thermistor or other).

  • 4 years ago

    Weather sites available on the Web are going to be way off the actual temperature outside your house where your heat pump is sitting. Accuweather temp vs your actual outdoor temperature could be wrong by over 10 Deg. F at times. This means you won't be switching from Gas to Heat Pump at the correct times and you won't get the savings in heating fuel costs. Further if the Accuweather is wrong in the wrong direction (telling your stat it is 40 DegF when it is actually 30 DegF at your location) then you run the chance of frying your compressor due to starting when it is too cold and if it does start you won't get much heat so your house won't heat up.


    Further what if you internet is down (WIFI router / ISP modem locks up or you ISP is doing service) You know this happens all the time and of course it will happen when you need it most.

    I would stay away from any thermostat that wants to use some website to switch between heating fuels. If the stat doesn't have a real hardwired outdoor sensor then don't buy it. All this fancy smart thermostat stuff is cool but I will take reliability over fancy technology any day. After all its only a thermostat do you really need to look at your indoor temp on your phone?


    Maybe smart stat is practical if you have some cabin up north you want to turn the heat on remotely the day before you arrive. But then again hopefully someone doesn't hack in and turn your heat up 90 for the entire month of Jan as that would be an expensive bill for not even being there.