Water alarms under every appliance that uses water. Maybe $10 each, and will save you thousands of dollars when you have a leak.

Edit - Amazon has a variety of different models. I get this one for most places, and it has a slide-out sensor base which is really cool. It makes it easy to get the sensor where you want it, like under a dishwasher without removing it. I also have one next to my kids bathtub so if they get to splashy ... alarm! It's been great for that reason alone lol.

If you want wifi-enabled, LaCrosse makes a whole system which IMO is pretty reasonably priced. I have one for my sump pump (water), hot tub and chest freezer (temperature based alarms, to prevent freezing or not freezing). There is an annual fee which I think is around $30 - $40, but I am okay with it since I would prefer to know right away if there's a problem.

Didn't see the last post, but here is what I bought awhile back for $30:

Amazon: La Crosse Alerts Mobile 926-25101-GP Wireless Monitor System Set with Dry Probe

Save a little bit buying that and 2 of these: La Crosse Alerts Mobile 926-25000-BP Wireless Monitor Add-On Sensor Only for existing La Crosse Alerts Mobile System

Works great, haven't had any problems with it for 8 months or so. Very useful in the summer where I am..

> LaCrosse TX60 gateway and station

$29.95, Prime. https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=pd_bxgy_201_img_2?_encoding=UTF8&psc=1&refRID=06BP6V42WNWY6V0R7GY8

Not stupid at all! You can use a portable hydrometer. I also have seen them built into mason jar lids.

I specifically use this system: http://www.amazon.com/gp/aw/d/B0081UR76G/ref=redir_mdp_mobile/176-6872666-1743244?fp=1&pc_redir=1427641992


It gives me the ability to remotely check my temps and RH, also records the data for viewing later on.

Hope that helps!

I would at least get one of those rolling portable AC units and keep on the side. If the main AC shits the bed, at least you're not running around like a maniac. 14,000 BTU unit will cost about $500. That's an awesome price to pay to sleep better at night.

Also, get a shitty network temperature sensor. This one is cheap and emails/SMS/app notifies you: https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=sr_1_2?ie=UTF8&qid=1479181276&sr=8-2&keywords=network+temperature+sensor

This is the one I'm planning to get for the freezer in the summer and my mini-fridge in the winter. DO pay attention to some of the comments though. If you are frequently away from home for long periods, you need a more expensive system.

https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=sr_1_7?keywords=refrigerator+alert&qid=1556036488&s=gateway&sr=8-7

Doesn't work with Smartthings but would do the job.

https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=sr_1_4?ie=UTF8&qid=1525124347&sr=8-4&keywords=freezer+monitor

I've been using one of these for a few months and am happy with it so far.

https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G

You can get a remote weather monitoring system. They often come with smartphone apps. Here's a cheap option:

La Crosse Alerts Mobile 926-25101-GP Wireless Monitor System Set with Dry Probe https://www.amazon.com/dp/B0081UR76G/ref=cm_sw_r_cp_apa_mZ-wxbDMMZ7QT

You're welcome. They come in all variations and sizes. Maybe install a marine battery and if you're game, a solar set up. You can also get something like this https://www.amazon.com/dp/B0081UR76G/ref=asc_df_B0081UR76G5374584/

https://www.amazon.com/gp/aw/d/B0081UR76G?psc=1&ref=ppx_pop_mob_b_asin_title

Get something like this: https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G

You can probably do a lot with the alerts it can send out.

If I was you I would use VNC viewer to remote into all of my machines to shut them down if that is needed. You can also get power bricks that you can remotely access. Since you spent the money on 100GPUs you should probably set something like this up anyway.

Non-mobile: http://www.amazon.com/dp/B0081UR76G/ref=redir_mdp_mobile/176-6872666-1743244?fp=1&pc_redir=1427641992

^That's ^why ^I'm ^here, ^I ^don't ^judge ^you. ^PM ^/u/xl0 ^if ^I'm ^causing ^any ^trouble. ^WUT?

This is what I use:

La Crosse Alerts Mobile 926-25101-GP Wireless Monitor System Set with Dry Probe https://www.amazon.com/dp/B0081UR76G/ref=cm_sw_r_cp_api_i_G9BVDbC1FSSYR

$30 bucks. Has high temp/humidity alerts and data logging

Is this just while you sleep with your reefer at a lot? Or parked at home with access to internet?

This might work http://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=sr_1_1?ie=UTF8&qid=1422499179&sr=8-1&keywords=lacrosse+temperature+monitor

A mobile wifi hotspot would enable it anywhere.

Similar to the last post, I have used one of these and it had served me well.

La Crosse Alerts Mobile 926-25101-GP Wireless Monitor System Set with Dry Probe https://www.amazon.com/dp/B0081UR76G/ref=cm_sw_r_cp_apa_i_sn8uCbX2BJG5G

There are basically 4 different sensor categories for my application.


  

1. USB logger

This plugs directly into the USB port on the Mac. They range wildly in price, sometimes costing close to $1k (which is way out of my budget).

Examples: TEMPerHUM, Omega, Lascar, Extech, TemperatureAlert, and more here

The problem is that, for whatever reason, these USB loggers are only compatible with Windows. The five above examples are Windows only.

The only logger that I have found that is Mac compatible is the Minnow. However, I spoke with the manufacturer and realized that it is not designed to be a real-time USB logger; the unit will quickly overheat. The workaround is to incorporate a USB relay switch to manually connect/disconnect the Minnow periodically from the Mac.

  

2. Bluetooth

Examples: Blustream, SensorPush, D'Addario Humiditrak, Eve Degree, and more here

The problem is that all of these products have an iOS app, but no macOS app.

But If I purchased the SensorPush sensor along with the $100 SensorPush WiFi Gateway, I can access the data over the internet.

But there are cheaper WiFi options, like the ConnectSense (won't be shipping until early 2019), Proteus, and La Crosse. But, I am hesitant to fully depend on an internet connection to get the data (i.e., if the internet goes down, then I would lose access to the data, which is not ideal).




  

3. RF

AcuRite sells a $13 Wireless Temperature and Humidity Sensor (model # 06002M) that transmits every 16 seconds using a 433 MHz wireless signal with a maximum range of 330'. This sensor is inexpensive because it is designed to be used with AcuRite Access and the AcuRite weather station products, which I do not want or need. It's all proprietary.

However, some people have reverse-engineered the radio signal to decode the data stream from this sensor if you have a USB RF receiver.

Examples:

• Acurite-00592TX-Decoder-ESP32a (C++)
  
  
• YouTube - Decoding Low Power Devices on MAC OSX Using RTL433
  
  
• rtl_433 (C) (device protocol #11)
  
  
• "Reverse Engineer Wireless Rain Sensors — Part 1"
  
  
• "Wireless Temperature Sensor"
  
  
  This path appears frustrating and difficult to a neophyte like me.
  
  
  
    
  
  

  4. DIY microcontroller
  

  
  Unlike the other 3 sensor categories, this looks like the one area where proprietary protocols are not in the way of progress. Once you get everything set up, accessing the raw data is a breeze.
  
  This is probably the most cost-effective option.
  
  Examples: Raspberry Pi + this $10 DHT22 sensor, Arduino, Espressif esp8266/esp32 wifi module
  
  The problem is that this is simply over my head. I have no real experience programming from the command line or really anything other than basic scripts. It would just be best if I paid someone to set this up for me, as I can easily envision myself spending 100 hours on this "simple" project.
  
    
  
  
  
  

Not an answer to your question but have you considered something like the following? (just one example, I have no personal experience with that specific one. The one I use at work is by monnit https://www.monnit.com )

https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=br_lf_m_7jtxmhgy5w2c7f3_ttl?_encoding=UTF8&s=home-garden

https://www.amazon.com/gp/aw/d/B01CW4BG4K/ref=mp_s_a_1_1?ie=UTF8&qid=1484074632&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=wifi+cam&dpPl=1&dpID=41YBQG2PpQL&ref=plSrch

https://www.amazon.com/Crosse-Alerts-926-25101-GP-Wireless-Monitor/dp/B0081UR76G/ref=pd_bxgy_201_img_2?_encoding=UTF8&psc=1&refRID=06BP6V42WNWY6V0R7GY8

https://www.amazon.com/gp/product/B005TY2MFS/ref=pe_225750_222264250_em_1p_0_ti