Temperature Monotoring

Look for a remote I/O mudule(could be an rtd or thermocouple input and out put ethernet to your pc) per floor. Google remote I/O module, honeywell has this type so as Schnieder,Abb and others.

M-system remote I/O module has cheaper solution to this, just click product data sheet for further info.

Thank You !

Will check, thank you for suggestions.

Any decent indoor outdoor thermometer with a cordless outdoor sensor will do what you need over the distances you want.

If you want to go corded same concept but with a wired unit. Cheap single unit type wired thermometers can be found on eBay for about $5. Just cut the temp sensor off and put a longer wire on it and you're good to go.

It depends on what you intend to do with this information and how accurately you need this information. If you just wish to log data then there are temperature data log sticks you can just drop in each refrigerator and retrieve them when you need data. If you will be alarming on a temperature trip then a PLC based system maybe the way to go or individual process control modules at the refrigerator.

That are refrigerators that I need to check periodically and to make sure that they work properly. I don't have wifi and it is concrete building. Have to go wired. Just need monitoring and 3-4 days stored data.

The simplest way would be a thermometer in each fridge, a pencil, a notepad, and a clock.

Yes, it is simplest way but people that work are not reliable. On this way I can remotely log in computer and check.

Seems to me you want to spy on your tennant's energy usage.

Ba Humbug.

Look out for temperature sensors with wifi transceiver module- if readily available. I am building one for some research project for some other application. Then you have to see how to write software etc.

One question I have is, why. What is the reason for monitoring the temperature of all these refrigerators. Are they storing temperature sensitive products? Are you trying to conserve or monitor some other "data"? Sometimes knowing the reason behind your question is all the information we need to reply with correct information. If you are truly looking for a solution, then you will have no problems telling us what you are trying to do.