I've never installed a door closer before and it was fascinating figuring out how they work. This one is a Dormakaba TS 83 BC EN 3-6 for doors up to 100kg.
I assume it works by storing the energy used in opening the door in a spring, and releasing it in a controlled manner when you let go of the door. You can adjust the strength of the spring for different weights and sizes of doors, or if it requires extra force to latch or fight pressure differentials for ventilation. The spring makes the door feel different when opening compared with a normal door - not exactly heavier, but there is more resistance. It was slightly odd at first, now previously solid feeling fire doors feel lightweight & insubstantial
It has a dial you can adjust to prevent it from flying into walls & furniture when pushed open quickly by gusts of wind or hasty musicians. The faster you push the door, the more it resists. The dial controls the amount of this resistance.
There's also a dial for the closing speed over most of the door angle. This can vary between really quick or almost not moving at all. A slow setting might be useful for musicians loading in gear.
Another speed dial controls the last 15 degrees before closing to make sure the door latches properly, yet not too powerfully to cause harm. It's really cool seeing this in action!
An unexpected bonus was that it can exert sufficient pressure on the door seals to keep the door closed without a latch. This meant I could remove the entire door latching mechanism, and fill the cavity routed out for it, so the door is now solid all the way through & better for sound attenuation.
I applied the pull side seal first on the overlapping bits of the new door face. The latch side of the door frame is slightly off square so the gap between face and door frame widens by a few millimeters as it nears the floor. I know it's the frame as the door is straight. I knew this before starting the door modifications, so tried to plan for it to some extent by leaving an extra layer of MLV at the corresponding place on the door to pad it out. It sill wasn't enough though, and the door is not completely airtight there. More work on this required another day.
If I had noticed this when beefing up the studs around that area and packing & adding extra screws to the door frame I could have straightened it out then. Now the gap between the frame and studs is sealed and all the plastering work has been done, I suspect it would be a major PITA to do this.
For the push side door seal I remove the hardwood "bank vault" trims before applying the seal. I held them in place so there was light compression along a foot or so of the seal without moving the fully closed door. Doing this bit by bit gives a consistent seal. A combination of sub millimeter fine tuning to ensure the seal is good by attempting to hammer thin panel pins through the trims while holding them in place was quite tricky.
The final seal is pretty good, a big improvement on before, but not quite good enough for a few feet at the off square part. I used a 6mm high D shaped foam gasket, and had hoped it would compress to about 4mm to allow for the off square pull side door frame. Unfortunately there isn't enough pressure from the closer to do this, I'll see if I can find a seal with greater squash variation for the part of the door. One of our exterior doors has an O profile rubber gasket that can go almost flat, something like that might do the trick.
Cheers!
Jennifer