Rethinking Magnetically Held Open Fire Doors are they a Solution or a Problem ? Take a look at a recent situation I witnessed when the power went out.

Magnetically or Mechanically held open doors have been around almost as long or in some cases longer than fire protection systems have been around.

They can be a very good way to prevent Fire doors from being blocked open with objects  and preventing there closing when there is a fire .

There is either a very simple magnet  or solenoid set up behind door to hold it and then release it when fire alarm or power goes out door drops closed

https://www.beaconcdl.com/basics-of-commercial-door-holders/

 A Mechanical door holder uses a Thermal Link  which went it melts drops the door closed or similar arrangement either arrangement works well and does it job  

with mechanical links being used mainly on big Roll up and Sliding doors in commercial and Industrial Buildings but I have seen them used on single man doors .

So ran across an interesting situation which could be catastrophic  if emergency lighting is not properly maintained in a building  and fails to come on when there is a fire. 

A customer of mine has a 3 story Office Building I maintain for him and power had been  out all day 

and at that point battery's in emergency lights which are designed for 90 minutes had drained .

the hall ways have no windows so there is little to no light available .

I took a flashlight with me as I went in to check building but unknown to me a mailman had come in front door was delivering mail to offices and got himself trapped in the 2nd floor hall when exit door inadvertently closed behind him and he was in total blackness. He could not find the door.  luckily he did not panic and yelled for help and found him. 

OK so here we have the door with magnet holding it to the left

OK here is the door now closed if your where in this building and power went off or Fire Alarm  and Emergency Lights failed to come on for what ever reason could you find your way out even if you knew this building ?

I could because i do not panic easily and would feel around till I found the door but precious minutes would be lost especially a hall filling with smoke.

This code section has never ever really been looked at or addressed by code since first ut in code  and thou doors could be held by battery for small time if code is properly meet  if battery's in lights have not been changed guarantee door battery's are dead too.

The other answer is Melting link but by time fire gets that hot it usually too late to save building and big issue is stopping smoke spread.

There has got to be a better answer