WEBVTT Kind: captions Language: en 00:00:00.120 --> 00:00:05.532 I’ve been struggling with a video script for a while that's suffering from a massive case of scope creep 00:00:05.532 --> 00:00:09.375 and it’s bothering me so much that I decided to shelve it for now. 00:00:09.375 --> 00:00:11.893 But, when one door closes… 00:00:12.815 --> 00:00:14.415 this thing might be why! 00:00:14.415 --> 00:00:16.641 This is a door closer. 00:00:16.641 --> 00:00:20.928 You see these everywhere in commercial buildings  and they’re pretty simple devices. 00:00:20.928 --> 00:00:24.656 But there’s one thing about them not enough people seem to know: 00:00:24.656 --> 00:00:26.357 these are adjustable! 00:00:26.357 --> 00:00:32.602 You can change their closing speed and speed them up to help a door which isn’t latching properly or, 00:00:32.868 --> 00:00:34.115 get this, 00:00:34.115 --> 00:00:39.875 slow it wayy down so the door stays open longer and it doesn't slam. 00:00:39.875 --> 00:00:46.585 Especially if you work in a hotel which is full of these and also people sleeping, that's a really good thing to know! 00:00:46.585 --> 00:00:51.237 All you need is an Allen wrench or screwdriver and someone to tell you how to do that. 00:00:51.237 --> 00:00:53.894 And I’ll happily play the role of that someone. 00:00:53.894 --> 00:00:59.172 I’ll also talk about why these are there in the first place,  how they work, and probably some other stuff. 00:00:59.172 --> 00:01:01.731 First, let me show you how to adjust these. 00:01:01.731 --> 00:01:04.778 Luckily, I have one installed on the door to the warehouse. 00:01:05.277 --> 00:01:06.804 Wait, you have a warehouse? 00:01:06.804 --> 00:01:07.603 Yep! 00:01:08.401 --> 00:01:09.704 wwwhy? 00:01:09.704 --> 00:01:12.590 For storing two of them, but that’s not important right now. 00:01:12.590 --> 00:01:14.332 We’re talking about door closers. 00:01:14.332 --> 00:01:19.825 So, this door, if I open it to 90 degrees then let it go, does this. 00:01:19.825 --> 00:01:23.634 It’s a nice and smooth swing all the way to the end and then, 00:01:23.634 --> 00:01:26.649 because there’s no latch hardware in the door right now, 00:01:26.649 --> 00:01:29.826 the door closer is the only thing holding the door shut. 00:01:29.826 --> 00:01:35.284 Which I’m pretty sure is a problem since this is a fire door but I didn’t do that so don’t look at me. 00:01:35.284 --> 00:01:43.523 Now, if we look at the door closer body we’re going to find that there are two little holes on the side with an Allen screw in each one. 00:01:43.523 --> 00:01:49.546 Sometimes there's a cover over the door closer body so if you don't see it right away, you might have to take that cover off. 00:01:49.546 --> 00:01:52.233 The holes are labeled L and S. 00:01:52.233 --> 00:01:55.983 And of I tighten the one labeled S, watch what happens. 00:01:55.983 --> 00:01:59.617 Now, the door is closing very slowly. 00:01:59.617 --> 00:02:02.303 That is, until it’s almost shut. 00:02:02.303 --> 00:02:06.153 Once it’s at about 15 degrees, suddenly it speeds up. 00:02:06.153 --> 00:02:07.728 Why’d it do that? 00:02:07.728 --> 00:02:10.814 Well, that’s kind of the whole point of those adjustments. 00:02:10.814 --> 00:02:18.639 Most door closers like this have two separate speeds: a swing speed (sometimes called sweep speed) and a latch speed. 00:02:18.639 --> 00:02:23.902 That’s what the L and S stand for (though they’re not always marked the same on every door closer). 00:02:23.902 --> 00:02:30.689 The swing speed, which is what I just adjusted, is the speed at which it will close the door over the majority of its travel. 00:02:30.689 --> 00:02:39.007 You usually want this to be fairly slow to help people with mobility issues or just to make getting through the door easier when you’re holding stuff. 00:02:39.007 --> 00:02:43.006 And in many jurisdictions the swing speed is actually codified. 00:02:43.006 --> 00:02:49.996 The Americans with Disabilities Act requires that the door take at least 5 seconds to close from 90 degrees. 00:02:49.996 --> 00:02:59.592 But when the door is about to shut, you might need it to speed up a bit to ensure it has enough momentum to successfully engage the latch. 00:02:59.592 --> 00:03:03.103 And that’s what the latch speed adjustment is for. 00:03:03.103 --> 00:03:07.030 Right now the latch speed on this closer is pretty moderate. 00:03:07.030 --> 00:03:14.353 But if I loosen that adjustment screw, the door shuts with a pretty significant thud regardless of how slow the swing speed was. 00:03:14.353 --> 00:03:15.112 [THUD] 00:03:15.112 --> 00:03:19.724 And if I tighten that screw, well the door no longer slams at all. 00:03:19.724 --> 00:03:22.423 Instead it shuts very gently. 00:03:22.423 --> 00:03:26.993 You can even adjust these so that the swing speed is faster than the latch speed. 00:03:26.993 --> 00:03:36.447 I don’t think there’s much reason to do that but if you did, the door would swing closed quickly but then slow down right near the end of its travel for a gentle close. 00:03:36.447 --> 00:03:39.475 And here’s what I’d really like to you to know: 00:03:39.475 --> 00:03:46.787 So long as the door will successfully latch under all conditions, you can have these be as gentle as you like. 00:03:46.787 --> 00:03:54.805 They do not have to slam the door, and in fact the whole reason this style of door closer exists is to keep that from happening! 00:03:54.805 --> 00:03:58.672 So if you install one of these and don’t actually adjust it to the door it's on, 00:03:58.672 --> 00:04:00.691 you’re making it very sad. 00:04:00.760 --> 00:04:02.368 But let’s back up a bit. 00:04:02.368 --> 00:04:05.920 Why do we want the door to close on its own anyway? 00:04:05.920 --> 00:04:11.151 Well, I already mentioned that this is a fire door  and that’s one of the main reasons. 00:04:11.151 --> 00:04:14.706 Fire, it turns out, is bad. 00:04:14.706 --> 00:04:18.097 There are some places where fire can be ok. 00:04:18.097 --> 00:04:21.657 Like for instance a fire… place. 00:04:21.657 --> 00:04:23.737 It’s really just called fire place, huh? 00:04:23.737 --> 00:04:30.084 Er, but where we don’t want it, and especially when we don’t expect it, fire is really dangerous. 00:04:30.084 --> 00:04:36.630 And if a fire breaks out in a building, fire doors are incredibly important for life safety. 00:04:36.630 --> 00:04:40.810 They compartmentalize a building and keep fire  from spreading to other areas, 00:04:40.810 --> 00:04:47.189 both by being a physical barrier and by restricting the supply of oxygen to the fire in progress. 00:04:47.189 --> 00:04:54.267 True fire doors can withstand the intense heat of a fire happening on the other side of them for more than an hour. 00:04:54.267 --> 00:04:58.732 But fire doors only work if the door is actually shut, 00:04:58.732 --> 00:05:07.279 so rather than let us forgetful humans forget to close them, we put door closers on them so they always close by themselves. 00:05:07.279 --> 00:05:15.708 Fun fact, in situations where we want there to be  a self-closing fire door but we also want it to stay open during not-fires, 00:05:15.708 --> 00:05:20.946 electromagnetic door holder-openers can be installed alongside a door closer. 00:05:20.946 --> 00:05:28.466 When powered on, these door holders attract  a small metal plate attached to the door to… hold it open. 00:05:28.466 --> 00:05:36.296 This is useful in situations such as a building with a long hallway that you ordinarily want unbroken for an unimpeded flow of people 00:05:36.296 --> 00:05:41.182 but which should be compartmentalized in the event of a fire to reduce spreading. 00:05:41.182 --> 00:05:50.312 The electromagnets are tied to the building’s fire alarm system, so they can be released if it detects a fire in progress or someone activates it manually. 00:05:50.312 --> 00:05:53.932 When the system cuts power to those electromagnets throughout the building, 00:05:53.932 --> 00:05:59.983 they all let go of whatever doors they’re holding open and the door closers close the doors. 00:05:59.983 --> 00:06:08.665 And of course this system is fail-safe - the door closers are  always trying to close the doors and the door needs to be actively held open, 00:06:08.665 --> 00:06:13.318 so if the holding system fails for any reason, the doors close. 00:06:13.318 --> 00:06:16.423 There are, of course, other reasons to keep doors shut. 00:06:16.423 --> 00:06:18.214 One of which is security. 00:06:18.214 --> 00:06:25.796 When there’s any kind of restricted access to a space, even something as relatively low-security as an apartment building’s lobby, 00:06:25.796 --> 00:06:33.082 you generally want doors to lock automatically and require a specific action to unlock them from the outside. 00:06:33.082 --> 00:06:40.101 But any automatic lock, even something as simple as a keyed door knob which is always locked from the outside, 00:06:40.101 --> 00:06:43.812 is pretty useless if the door can be left open. 00:06:43.812 --> 00:06:50.693 So you slap on a door closer to make sure that door always closes behind you and always locks. 00:06:50.693 --> 00:06:55.078 Of course you can defeat a door closer with a doorstop or... 00:06:55.078 --> 00:07:04.465 like, a brick but that takes a conscious effort and for people casually coming in and out throughout the day, the door closer ensures the building is secured. 00:07:04.465 --> 00:07:07.419 Actually, quick note about doorstops. 00:07:07.419 --> 00:07:11.941 They are the enemy of a secure building and also fire safety. 00:07:11.941 --> 00:07:17.833 The temptation to use them is the reason those  electromagnetic door holder opener thingies get installed. 00:07:17.833 --> 00:07:26.249 When the need to keep the door open is obvious but the need for it to close in a fire is safety critical, they’re a great choice. 00:07:26.249 --> 00:07:32.422 But there are always going to be random situations where you need a self-closing door to be held open, 00:07:32.422 --> 00:07:39.449 so certain people would like me to tell facilities managers about delayed-action door closers. 00:07:39.449 --> 00:07:40.971 They exist! 00:07:40.971 --> 00:07:45.890 They act like any other door closer except when you open the door completely. 00:07:45.890 --> 00:07:52.202 When opened all the way, an internal mechanism is tripped which holds the door open for a minute or two. 00:07:52.202 --> 00:07:54.167 And then it will close. 00:07:54.167 --> 00:08:04.967 This is a great compromise for situations like helping workers who need to move bulky tables into an event space which has critical fire doors that cannot be left open. 00:08:04.967 --> 00:08:11.232 Alright and then the last major reason  to keep a door shut besides safety and security is energy. 00:08:11.232 --> 00:08:14.358 It costs money to keep buildings heated and cooled, 00:08:14.358 --> 00:08:16.835 and we’re not paying to heat the outside! 00:08:16.835 --> 00:08:23.732 So exterior doors often have door closers to make sure nobody leaves them open and makes Dad angry. 00:08:23.732 --> 00:08:26.671 However, there’s a dual-role there in that case. 00:08:26.671 --> 00:08:31.999 Exterior doors, when left open,  can be a lovely supply of oxygen for fires 00:08:31.999 --> 00:08:36.823 so self-closing exterior doors are not strictly for energy saving purposes. 00:08:36.823 --> 00:08:38.277 But they sure help. 00:08:38.277 --> 00:08:44.120 Fun fact, the reason revolving doors exist is because they are functional airlocks. 00:08:44.120 --> 00:08:49.206 High-traffic buildings in areas where it gets real cold have them almost as a rule 00:08:49.206 --> 00:08:59.968 because the four panels of rotating glass mean the door is never actually open so there’s never a blast of cold air coming in as people enter and exit the building. 00:08:59.968 --> 00:09:03.002 Just little sections of air get exchanged. 00:09:03.002 --> 00:09:10.419 Of course there are accessibility concerns there so generally there are also standard doors with powered openers for those who need them, 00:09:10.419 --> 00:09:14.952 but you often find signage thanking you for using the revolving door if you can. 00:09:14.952 --> 00:09:19.003 Vestibules with a door on each end are  another way to achieve air locking - 00:09:19.003 --> 00:09:24.196 though in order to be truly effective both sets of doors  should never be open at the same time. 00:09:24.196 --> 00:09:28.400 And when the doors are automated, uh that happens a lot. 00:09:28.400 --> 00:09:36.589 I’d kind of like there to be a mode you can turn on in extreme cold which forces people to wait in the vestibule until the first door has closed 00:09:36.589 --> 00:09:41.310 but that would be confusing and potentially unsafe  so I can understand why I’ve never seen that. 00:09:41.310 --> 00:09:48.106 OK, so with all those particulars out of the way,  how is this thing actually closing the door? 00:09:48.106 --> 00:09:50.766 Well, the answer's simple: 00:09:50.766 --> 00:09:52.517 With a spring. 00:09:52.517 --> 00:09:56.574 In fact a simple spring is all you need to keep a door shut. 00:09:56.574 --> 00:10:05.128 If you put one somewhere such that it gets compressed as the door opens, then the spring is gonna push the door shut once it's let go. 00:10:05.128 --> 00:10:08.962 And this here is a spring hinge! 00:10:08.962 --> 00:10:11.121 This is technically a door closer. 00:10:11.121 --> 00:10:13.701 Look, it even says UL listed door closer bod. 00:10:13.701 --> 00:10:14.656 Body. 00:10:14.656 --> 00:10:18.891 These are fairly common in household environments thanks to building codes. 00:10:18.960 --> 00:10:24.337 I have a couple on the door between my garage  and the rest of my home because that wall is a firewall 00:10:24.337 --> 00:10:28.516 and you really don’t want that door  left open in case there’s a car fire. 00:10:28.516 --> 00:10:30.363 Which can happen. 00:10:30.363 --> 00:10:34.781 These simple hinges contain a spring which is compressed as the hinge opens, 00:10:34.781 --> 00:10:40.422 meaning the hinge will always close unless  someone is actively pushing the door open. 00:10:40.422 --> 00:10:44.881 These work mostly fine but… they slam doors. 00:10:44.881 --> 00:10:46.283 Real bad. 00:10:46.283 --> 00:10:49.123 When the door is fully open and then let go, 00:10:49.123 --> 00:10:55.075 it consistently picks up speed as it travels  and by the end of its travel it’s moving quite fast. 00:10:55.075 --> 00:10:59.062 So when it meets the frame [SLAM] there’s quite a bang. 00:10:59.062 --> 00:11:04.909 That’s of course annoying but also can cause injuries if people get their fingers in the wrong place at the wrong time. 00:11:04.909 --> 00:11:11.739 That has even caused lawsuits when they were used in public places and public fingers got publicly pinched in public. 00:11:11.739 --> 00:11:15.994 And besides that little issue, these don’t always latch the door. 00:11:15.994 --> 00:11:18.427 The spring in these isn’t very strong. 00:11:18.427 --> 00:11:24.764 I mean it seems quite strong when this isn't attached to a door but with the massive amount of leverage a door provides 00:11:24.764 --> 00:11:32.716 the spring hinges don’t push back with all that much force, so if you let a door go when it’s already close to its closed position, 00:11:32.800 --> 00:11:39.840 these will hold it mostly shut but they may not  have enough oomph to actually engage the latch. 00:11:39.840 --> 00:11:42.427 So… eventually we got these things! 00:11:42.427 --> 00:11:46.150 These also have springs, but there’s a twist. 00:11:46.150 --> 00:11:52.943 A second mechanism is fighting the spring to regulate the speed at which this closes the door. 00:11:52.943 --> 00:11:58.937 There were several different ways that was accomplished over the years, and some of the alternatives to this one still survive. 00:11:58.937 --> 00:12:03.781 But this hydraulic mechanism is by far the most common we see today. 00:12:03.781 --> 00:12:08.999 The actual closing force is provided by a spring pushing on a sliding rack. 00:12:08.999 --> 00:12:14.058 That rack engages with a pinion gear which this arm is attached to. 00:12:14.058 --> 00:12:16.693 When I force the arm in this direction, 00:12:16.693 --> 00:12:20.558 the rotating pinion slides the rack such that the spring is compressed. 00:12:20.558 --> 00:12:27.669 And when I let go, the spring pushes the rack back in the other direction and the arm returns to its original position. 00:12:27.669 --> 00:12:34.945 But the rack the spring pushes on is also attached  to a piston inside a hydraulic cylinder filled with oil. 00:12:34.945 --> 00:12:38.433 And that’s where the speed control comes from. 00:12:38.433 --> 00:12:44.873 When you push the door open, a check valve opens which allows the fluid to pass from one end of the cylinder to the other, 00:12:44.960 --> 00:12:49.370 thus the piston can travel through the hydraulic  fluid mostly unimpeded. 00:12:49.370 --> 00:12:53.279 But when it starts moving backwards via the force of the spring, 00:12:53.279 --> 00:12:57.467 that valve closes and now the piston is stuck. 00:12:57.467 --> 00:13:00.609 The hydraulic fluid has locked it in place. 00:13:00.609 --> 00:13:06.451 But there are two additional paths oil can take to move between the two halves of the cylinder. 00:13:06.451 --> 00:13:12.396 And those paths each have a valve inside which can restrict the flow of the fluid. 00:13:12.396 --> 00:13:14.500 And guess where those valves are? 00:13:14.500 --> 00:13:16.481 Here and here. 00:13:16.481 --> 00:13:22.070 The latch and swing speed adjustments are in fact valves which, when turned, 00:13:22.070 --> 00:13:26.733 increase or decrease the speed at which fluid can flow through them. 00:13:26.733 --> 00:13:30.691 And that in turn restricts the speed of the closing mechanism. 00:13:30.691 --> 00:13:36.229 When you tighten these valves, you restrict that flow more which slows the mechanism down. 00:13:36.229 --> 00:13:42.563 In fact you can completely close them and, well, the door closer then becomes truly stuck. 00:13:42.563 --> 00:13:49.427 Or you can completely open them and then the spring is basically free to close the door as fast as it can. 00:13:49.427 --> 00:13:54.167 Careful, though, because you can remove these plugs and that’ll let the hydraulic fluid out 00:13:54.167 --> 00:13:58.353 which is A) unpleasant and 2) will break the door closer. 00:13:58.353 --> 00:14:04.370 Actually, on that note, if you ever see one of these on a door with streaks of grossness coming down from it, 00:14:04.370 --> 00:14:09.220 the seals inside have probably failed and the hydraulic fluid leaked out. 00:14:09.220 --> 00:14:16.965 That door closer needs to be replaced if you don’t want it to slam because, well, its damping mechanism is effectively gone. 00:14:16.965 --> 00:14:24.238 But anyway, the two different closing speeds are achieved by the differing paths of the oil bypasses. 00:14:24.238 --> 00:14:33.275 During the bulk of the door’s travel, the latch speed bypass doesn’t actually do anything because both of its ports are on the pressurized side of the cylinder. 00:14:33.275 --> 00:14:42.871 But once the piston gets past this point, those ports are now on either side of it so they become a second bypass with its own dedicated speed setting. 00:14:42.871 --> 00:14:45.208 Pretty simple and pretty clever. 00:14:45.208 --> 00:14:48.254 But it’s not actually that simple. 00:14:48.254 --> 00:14:55.902 I want to make you aware of some particulars which are important to keep in mind both when making adjustments and when installing a door closer. 00:14:55.902 --> 00:15:01.910 For a start, these come in different sizes which really just means different spring strength. 00:15:01.910 --> 00:15:09.844 The spring inside here is the only thing that actually  produces closing force so you need to make sure it provides the appropriate amount. 00:15:09.844 --> 00:15:15.325 Wider and bigger doors need stronger springs than smaller, narrower doors. 00:15:15.325 --> 00:15:18.250 And when you encounter a door that’s “heavy” - 00:15:18.250 --> 00:15:25.943 it’s likely got a door closer on there that’s just too big for it and you can’t exert enough leverage to easily overcome the spring. 00:15:25.943 --> 00:15:33.804 Then again, some models - including this one - allow you to adjust the spring tension so this is sold as sizes 1 through 4, 00:15:33.804 --> 00:15:38.505 appropriate for any interior door up to 3 feet six inches wide. 00:15:38.505 --> 00:15:42.876 Now, while the spring is the only thing directly providing closing force, 00:15:42.876 --> 00:15:52.618 thanks to our old pal momentum the door’s speed as it closes will affect its latching force and that’s why the latch speed adjustment exists. 00:15:52.618 --> 00:15:58.675 If there’s a door which needs a bit of a shove to positively latch, this will give it that shove. 00:15:58.675 --> 00:16:04.896 If the latch operates smoothly and the door fits well within its frame, that shouldn’t be necessary, though. 00:16:04.896 --> 00:16:12.603 The spring force alone will shut the door, but there’s a weird extra thing to consider which is easy to miss: 00:16:12.603 --> 00:16:20.157 in modern buildings, HVAC systems can produce air pressure imbalances between rooms or between the inside and outside. 00:16:20.157 --> 00:16:27.792 If those pressure imbalances are significant enough, they can  overcome the spring force and keep the door from completely closing. 00:16:27.792 --> 00:16:37.180 This means that a door closer which gently and successfully latches a door in some conditions might not latch it when the HVAC system is running, 00:16:37.180 --> 00:16:44.377 and in that case you have to adjust it for the worst case scenario and there will be times it closes with a bit of a slam. 00:16:44.377 --> 00:16:50.926 And by the way, I have not touched the adjustments  on this door closer and watch how it behaves out of the box. 00:16:52.796 --> 00:16:57.358 Yeah, this would absolutely slam a door without adjusting the latch speed. 00:16:57.358 --> 00:17:06.000 But when you consider that the manufacturer of this is most concerned with its products doing their basic job in as many situations as possible, 00:17:06.000 --> 00:17:10.626 it makes sense that they’d sell them with the latch valve pretty wide open. 00:17:10.626 --> 00:17:15.010 They’re counting on the installers to make that adjustment when it’s possible, 00:17:15.010 --> 00:17:21.533 but lots and lots and lots and lots and lots and lots of people just never touch it. 00:17:21.533 --> 00:17:25.269 Ask anyone who has ever stayed in a hotel. 00:17:25.269 --> 00:17:28.342 Fun fact, I used to work in the hotel industry 00:17:28.342 --> 00:17:32.358 and one of the first things I did at a new property when I had some time on a slow day 00:17:32.358 --> 00:17:38.067 was go around the building and adjust all the door closers so they didn’t slam anymore. 00:17:38.067 --> 00:17:47.825 Almost none of them had been touched at all since the hotels were built, so almost every guestroom door slammed shut with quite the bang. 00:17:47.825 --> 00:17:49.611 Same with the stairwell doors. 00:17:49.611 --> 00:17:55.935 And that’s pretty annoying in the middle of the night, so I simply took the time (which wasn’t that much time at all) 00:17:55.935 --> 00:17:59.882 to go around, open every door, and adjust the closers. 00:17:59.882 --> 00:18:04.188 I slowed them down as much as I could while making sure that they latched properly, 00:18:04.188 --> 00:18:08.595 and then I sped them up just a tad to account for varying conditions. 00:18:08.595 --> 00:18:17.307 Some doors had trouble latching and I had to leave them slamming somewhat, but I was able to silence the vast majority of the doors. 00:18:17.307 --> 00:18:20.769 It wasn’t much of a task, but nobody had thought to do that, 00:18:20.769 --> 00:18:26.187 and this is why you need a weird obsessive nerd somewhere on your staff! 00:18:26.187 --> 00:18:30.527 Now, to be honest, this bugbear of mine is the main reason I made this entire video 00:18:30.527 --> 00:18:35.912 and mostly I’m concerned with people knowing how to adjust door closers which already exist. 00:18:35.912 --> 00:18:43.318 But I would like to briefly talk about mounting these to a door  because that’s way more complicated than it seems at first glance. 00:18:43.318 --> 00:18:51.811 You’ll notice that the pinion gear which actually turns the door closer arm has attachments coming out on both the top and the bottom of the body. 00:18:51.811 --> 00:18:55.773 That’s because some doors are hinged on the right, while others are hinged on the left, 00:18:55.773 --> 00:18:59.059 so which way you need the arm to swing will change. 00:18:59.059 --> 00:19:04.641 But also, you may need this installed on the push side of a door or the pull side of the door. 00:19:04.641 --> 00:19:10.536 And sometimes you need to mount the closer body to the frame of the door and other times you need to attach it to the door itself. 00:19:10.536 --> 00:19:17.277 And you’ll also need to decide if you want the door to only open to 90 degrees or if you want a full 180 degree swing. 00:19:17.277 --> 00:19:21.029 All of those factors change how you need to mount this, 00:19:21.029 --> 00:19:27.556 which linkages you need, and how long those linkages need to be, and how they behave, and it’s confusing. 00:19:27.556 --> 00:19:34.683 These are the instructions for mounting this door closer, and while it’s not rocket surgery it’s more involved than you’d think. 00:19:34.683 --> 00:19:39.143 And as with any rabbit hole you go down, it just keeps going. 00:19:39.143 --> 00:19:44.504 This is by far the most common type of door closer but there are many, many more. 00:19:44.504 --> 00:19:48.571 Some are installed in the floor so they can operate frameless doors, 00:19:48.571 --> 00:19:52.732 others are concealed within the door jamb which provides a sleeker look. 00:19:52.732 --> 00:19:58.775 I’m sure many of those are adjustable in the same way as this but I’m gonna leave that to you to figure out. 00:19:58.775 --> 00:20:02.962 Oh right, and also many door closers have a back-check adjustment. 00:20:02.962 --> 00:20:08.542 Often labeled BC, that provides some speed restriction as you open the door. 00:20:08.542 --> 00:20:14.430 It generally only kicks in at the very end of the door’s sweep to slow it down before it opens completely. 00:20:14.430 --> 00:20:20.784 This can be a necessary thing, especially on exterior doors which might fling open if the wind catches them, 00:20:20.784 --> 00:20:26.605 but it also prevents door flinging humans from damaging  your doors by stomping out particularly angrily. 00:20:26.680 --> 00:20:30.488 Then of course there are powered door closers which also open doors, 00:20:30.488 --> 00:20:33.213 often activated with a button near them. 00:20:33.213 --> 00:20:39.239 They use an electric motor to open the door and hold it open for a short while before letting it close again, 00:20:39.239 --> 00:20:45.321 which makes entering and exiting a building easier for wheelchair users or anyone who might need help with a door. 00:20:45.321 --> 00:20:49.262 You don’t often see those as much as you used to, at least in my area, 00:20:49.262 --> 00:20:54.650 since most businesses have chosen to have fully automatic doors which respond to motion sensors, 00:20:54.650 --> 00:21:02.960 but they stick around in lots of places where traffic volume doesn’t justify going that far yet which require disability access. 00:21:02.960 --> 00:21:08.912 I’ve mostly been focusing on commercial door  closers but there are some common types you find at home. 00:21:08.912 --> 00:21:15.912 I already mentioned these spring hinges but if you’ve got a screen door it’s probably got one of these door closers on there so it doesn’t flap about in a storm. 00:21:15.912 --> 00:21:23.071 This is just a spring in a tube pulling on this stick, 00:21:23.071 --> 00:21:28.332 and when you pull the stick out the spring fights you and pulls the stick back inside. 00:21:28.332 --> 00:21:33.684 It uses air pressure to dampen the spring’s return, and even these are adjustable! 00:21:33.684 --> 00:21:35.227 At least, many of them are. 00:21:35.227 --> 00:21:41.771 This one has a screw at the back which you can tighten to restrict the flow of air leaving the cylinder which slows it down. 00:21:41.771 --> 00:21:44.031 But then at the end you get a little toot. 00:21:44.031 --> 00:21:44.688 [toot] 00:21:44.688 --> 00:21:47.163 Turns out this has a latching speed, too! 00:21:47.163 --> 00:21:48.975 Though that’s not adjustable. 00:21:48.975 --> 00:21:55.009 But at this point, I’m just rattling on so why don’t we give this video a proper ending where it comes to a close? 00:21:56.081 --> 00:21:57.681 I had to, okay? 00:21:57.681 --> 00:22:04.656 I want to give a shout-out to Deviant Ollam who I reached out to after watching this amazing talk of his on fire codes. 00:22:04.656 --> 00:22:12.185 I figured he’d probably have a good list of door closer  trivia and he delivered most excellently so thank you for your script consultancy. 00:22:12.185 --> 00:22:19.757 There are a lot of things in our everyday lives that are just… there and you’re not gonna think of unless somebody brings them to your attention. 00:22:19.757 --> 00:22:25.995 And it is my sincere hope that at least a few facilities managers out there (or just bored people who work in buildings) 00:22:25.995 --> 00:22:33.003 give their door closers a little love so they can stop annoying  people as they do their very important jobs. 00:22:34.000 --> 00:22:36.417 ♫ adjustably smooth jazz ♫ 00:22:38.886 --> 00:22:40.463 This might be why! 00:22:40.463 --> 00:22:42.075 This is… 00:22:42.075 --> 00:22:43.178 not gonna work. 00:22:44.250 --> 00:22:45.904 I screwed that uuuuuuup. 00:22:45.904 --> 00:22:48.927 ...speed them up to help a door which isn’t lassing prop… 00:22:48.927 --> 00:22:50.334 [painful sigh] 00:22:51.531 --> 00:22:52.418 brrrr 00:22:52.418 --> 00:22:55.519 ...and speed them up to help a door which isn’t lapping prop… 00:22:55.519 --> 00:22:56.388 crfff 00:22:58.133 --> 00:22:58.890 brrrp! 00:22:58.890 --> 00:23:00.282 So don’t look at me. 00:23:00.282 --> 00:23:02.608 Now, if we look at the door closer body. 00:23:02.608 --> 00:23:04.493 I don’t like that deliver AT all. 00:23:04.493 --> 00:23:07.604 And in fact the whole reason this style of [bleep] 00:23:07.604 --> 00:23:09.982 These do not have to slam the door! 00:23:09.982 --> 00:23:16.054 And in fact the whole reason they exist… I need to back  up because I skipped a very important caveat. 00:23:16.054 --> 00:23:18.056 …installing a door closer. 00:23:18.056 --> 00:23:21.712 For a start [thud] these… well that was… 00:23:23.059 --> 00:23:26.400 ...wonderful. Good time was had by all, I'm pooped! 00:23:26.400 --> 00:23:29.068 Yes, I should be - good lord what is happening in there? 00:23:29.068 --> 00:23:31.847 See, now that's why you need door closers. 00:23:31.847 --> 00:23:35.682 To localize the aurora borealis entirely within the kitchen. 00:23:35.682 --> 00:23:38.917 It just makes sense!