What you see to the left is a very simple $20.00 Low Temperature Switch which warns when a buildings temperature goes below 40 degrees F. which uses a simple therm o disk made by United security products
By NFPA 72 Fire Alarm code you are required to install these or similar manufacturers simple switches any time sprinklers are installed where the weather gets below freezing like where in Live in Western Pa. there are even more sophisticated units you can dial in exactly when you want notified when the buildings temperature drops or rises above what you want.
Yet how many times I go to take over a system or work on one as a sub contractor and there is no low temp switch any where.
there required yet there not installed and most inspectors do not even know there required so up to 98% of the sprinkler systems out
there in Pa and other states do not have them a simple $ 20 switch which can warn pipes are freezing vs thousands of dollars in damage yet no one uses them. Why many installers do not know they need them despite being certified by NICET or other agency and the reason no one mentions them. Too many company's think its the HVAC contractors job to install them wrong its the company's installing the sprinklers and the fire alarms to jointly make sure one or the other company has installed them. But as usual who ever reads a code book let alone owns one and these idiots are out there installing systems incorrect and AHJ are passing them because they have no proper training either. The result every year when the temps go down below freezing for a week or more all you hear coming over the Fire scanner is calls for broken sprinkler pipes, which are flooding buildings and damaging electric systems etc. dam shame but we go thru this every winter around here. Due to ignorance ,arrogance ,greed and stupidity.