Mini Wireless Temperature & Humidity Sensor

This is a great product, and does exactly what it promised. The price is currently a little bit steep (~$40) per unit when compared to others, but you get back a well working and useful device. The Bluetooth range is incredible, even with the signal blocked by stainless steel doors.The reason for this purchase was a kitchen refrigerator and freezer combo that appeared not to cool well, or at least very inconsistent. Before purchasing two of these units, we cleaned out the coils located under the combo that were full of dust. First with a coil brush to get the biggest dust bunnies out, then a final clean with a battery powered little leaf blower (Makita). The leaf blower did the trick and made everything look like new. This required unplugging the combo and removal of back plate to make compressor area accessible for cleanout.Moving on from cleaning the combo, I reviewed multiple solutions of how to monitor temperature in both refrigerator and freezer compartments. First I was set on some high grade mechanical temperature meters, but after thinking about it for a little longer I didn't want to have to open and close the doors all the time in order to see what the temperature was. Also, the temperature is always moving down when the compressor is running, and up when it is not. The refrigerator and freezer operate in a bandwidth, and when it is equipped with auto-defrost you might think the freezer is not working while it is just cycling through a defrost cycle.Then the sensor itself; I'm tech savvy due to my profession as an engineer, so I typically try to buy quality over quantity. First thing I did was checking it's accuracy with some lab grade equipment, and readings were well within 35% of the maximum allowable tolerances (see specs). These units can easily be calibrated via the app, which I did, although they would have been fine without these minor adjustments.The app is easy to use, and has hourly, daily, weekly, monthly and yearly graphs that show min/max and average for selected time range. There is an option to download all data points to a computer or your phone. Very useful to see performance over time, and whether or not it is time to clean the coils. With an auto-defrost feature, you'll be able to tell exactly how many times it runs this feature. If it starts happening more often, you may have door seals that are worn, or usage might have been going up (open door more often, and this cycle runs more often. It was a surprise seeing the freezer go up to 41°F about once a day.That gets me to one point of improvement I would like to see in the app; there needs to be a delay that can be set before it warns you when temperature reaches a certain level for a determined time. For instance, I set my freezer alarm at 9°F. I want the app to notify me only when the temperature is above this temperature for more than 2 hours. Currently, I get notifications every time the auto-defrost cycle is running, which leaves temperatures above 9°F for a little over an hour. For this reason I had to remove the alarm, or basically set it at over 44°F, which now will not warn me anymore if freezer contents are over 9°F for an extended amount of time.Last thing I would like to mention is that you'll need to give the app continue location access, which is only related to Bluetooth access. You can turn it off to allow only when you open the app, but it would then not give you an alarm anymore unless you open the app. Without alarms set you could just give access only when the app is open.This item is definitely a winner, but I still hope Tempi.Fi will add a delayed alarm feature to their app so it can be used in refrigerators or freezers with auto-defrost function, or to limit alarms when loading groceries. It comes with double sided 3M tape, but instead I used "3M Dual Lock" velcro so I easily can take the units out when replacing batteries (they should last 1 year). Perhaps another improvement idea. I hope their will be a gateway soon, as they state they are working on it, and it would allow for temperature checks wherever you are.

I bought this because the display on a lab freezer at work was reading all sorts of weird temperatures and I wanted to track the actual real temp and compare it to the readout. I wanted something inexpensive and easy to use. I was so excited when I found the Temp.fi during an Amazon search. This little monitor came through in a big way. It logs data even when my phone is away and then uploads immediately, as soon as my phone is in range again. The temps it logs look spot on for what the freezer should be, the freezer display is obviously malfunctioning and now I have the data to show the company for repair. I love the ease of use. I just downloaded the app on my phone and put the monitor into the freezer. The app shows the temperature and humidity graphs by hour, day, week, month, or year, and you can toggle between each with one click. This freezer is a frost-free model and the temp.fi monitor shows those defrost cycles accurately. I'm not really using the humidity function, but I could see how it could be really helpful in certain applications. This was exactly what I needed. I could see using it around the house, as well.

We live in a large concrete home. My shop is on the other side of a steel-embedded, concrete wall. It is important to keep the shop equipment and tools dry. Temp.fi helps me do that; the signal penetrates the steel and concrete wall easily.I also have a Temp.fi in the concrete enclosed vault. Again, the signal is easily readable.Finally, I have another Temp.fi in the lower master suite and it works quite well, too.I am very happy with the ease of use of this device. It keeps me from running all over this large place looking at humidity gauges. I will add more Temp.fi devices in the near future.

It is easy to hide in an animals enclosure, refrigerator, or freezer and works in most environments. It only takes about 5 minutes to set up and is very accurate. It connects via Bluetooth so you have to be within range of the device but once you are and can recover all of its recorded data to check any temperature or humidity spikes/dips. Its battery is also very easily replaced but is not necessary as the one it comes with lasts a very long time. Not connecting via wifi is its only flaw.

For products like these, the associated smartphone app is at least as important as the physical product itself. The sensors are good and the smartphone app is good too and according to the app's page on the iOS app store, the app doesn't collect any data from users, unlike the app from another company whose temperature sensor I was considering buying.