7

image of smoke alarms in Mad Men

From this picture from Episode 2 Season 1 of Mad Men, I have circled two cigarettes in red and three smoke alarms in black on the ceiling.

I am assuming they are smoke alarms. If they are, why are they not triggered by smoke coming from cigarettes in the office?

Improve this question
11
  • 1
    Were smoke detectors even a thing back then? I live in Germany, and we are a lot more regulation-happy than the US, but even here, smoke detectors only became mandatory in residences in all 16 States a year ago. (In some States, they have been mandatory for new buildings and renovations for 10 years, but the last grandfather clause ran out in Saxonia on New Year's Eve 2023.) In offices, they are still not mandatory, except in one State. They didn't even become affordable until the 1970s.
    – Jörg W Mittag
    Commented Dec 13 at 19:08
  • 9
    Why would there be smoke alarms that could be triggered by cigarette smoke in an era where tons of people smoked in an office? Also, cigarette smoke setting off smoke alarms is a rare event.
    – BCdotWEB
    Commented Dec 13 at 22:37
  • 9
    I very much doubt those are meant to be smoke detectors. Small, commercially viable smoke detectors didn’t become available until the early 1970s
    – Todd Wilcox
    Commented Dec 14 at 3:43
  • 4
    In that era, if that's how they worked they'd have been a non-starter as a product.
    – Mazura
    Commented Dec 14 at 6:56
  • 2
    Even today that would be an unusual density of smoke detectors, 3 visible in one part of a room. Recessed sprinklers seems much more likely
    – iandotkelly ♦
    Commented Dec 15 at 0:07

3 Answers 3

Reset to default
40

They probably aren't smoke alarms. That seems like way more smoke alarms than you would need, especially with that spacing.

I think it's more likely that they are concealed/recessed sprinkler heads. When they are exposed to enough heat, a solder joint will melt/break and the sprinkler head will drop down and begin spraying water.

In a time when everyone was smoking inside, this would be pretty practical for fighting real fires while not giving false alarms all the time from cigarette smoke.

Also, just looking around my office, the spacing between heads is very similar (ours have six 2'x2' tiles between each head, this picture seems to show five between each).

Improve this answer
7
  • 6
    OT: The gym where I swim has twelve sprinkler heads over the swimming pool. In case, you know, the pool catches fire I guess.
    – Crash Gordon
    Commented Dec 14 at 17:19
  • 9
    @CrashGordon - pool covers are often made of flammable materials
    – Valorum
    Commented Dec 14 at 18:55
  • 2
    Was the pool installed from the building's initial construction or did the gym do a major renovation at lease and have the pool added ex post? More likely indoor structures may require so many sprinklers per x square feet whether or what is present beneath.
    – civitas
    Commented Dec 15 at 18:40
  • The rosettes are held shut by solder, that generally melts around 60, 70, or 120 degrees C. They take ages to start spraying water and the building is normally well alight before they trigger. Cigarette do not release that much heat else they'd burn faster.
    – Criggie
    Commented 2 days ago
  • 1
    @Criggie in a modern system there are additionally high-pressure pumps triggered by the fire alarm system - when they're tested they make an awful racket - but hat alone isn't enough to release the water. There are valves as you say, and some still use an alloy like Fields metal (others use a glass bulb to hold them shut, that breaks when the contents expands). But in any case you'd need to hold a flame or other heat source up to them directly to trigger them - even a hairdryer needs to be incapable of doing it accidentally
    – Chris H
    Commented 2 days ago
23

JMac's answer is correct; those probably aren't smoke detectors.

Two additional points:

  1. Smoke detectors weren't strictly mandated until starting in the 1970s

    US Department of Commerce (1974, "Fire Detection: The State of the Art*):

    In past years building and fire codes made little or no mention of requirements for fire detection in buildings. The chief concern centered around evacuation alarms activated by manual pull stations. Recently code officials at the local and state levels, as well as the model code authorities, have begun requiring detection in various types of occupancies , notably multi-family residential. The extent of this move to require detection is so great that a detailed treatment and analysis of all requirements is beyond the scope of this work.

    (Mad Men S01 is set in 1960.)

    There were legal battles against such laws (and their cost). NYT (1978, "New York City High‐Rise Fire Law Is Reinstated by Appellate Division"):

    The opinion cited a number of cases in which safety requirements had cost as much as 30 percent of a property's assessed valuation

  2. Even today, smoking does not usually set off smoke detectors.

    Cigarette smoke particles are much smaller than the particles from say burnt toast. Which is why burnt toast often sets off the smoke detector while smoking doesn't.

    From a fire protection company (SSI, 2024):

    Can Cigarette Smoke Set off My Fire Alarm?

    In short, yes, it can. But reports of cigarette smoke triggering a fire alarm are rare. After all, the smoke from a single cigarette is relatively insignificant and dissipates quickly.

    And in the past, smoke detectors were even less sensitive:

    modern smoke detectors are more sensitive than models from years past. This allows them to detect fires faster, but it also makes them more vulnerable to going off because of cigarette smoke.

    Chatham County NC:

    Cigarette Smoke

    Normally, a smoke alarm will not respond to cigarette smoke unless it is very concentrated, e. g, a large group of smokers in the same room. Standing close to the unit and blowing into it can cause it to respond, but this is not a normal situation, either.

    Quora anecdotes:

    I’ve had 2 people in here with me smoking cigarettes and reefer and there was a stick of incense going and the alarm didn’t even peep. But just let one little wisp of smoke come out of my oven and the damn thing nearly has a stroke.

    …

    I've lived in smokers houses all my life, I'm even a smoker. Never once have I or anyone I know set off smoke alarms from their cigarette smoke even when there were 4 pack a day smokers in the same room for a couple hours they didn't set it off

Improve this answer
11

Not smoke alarms

According to this link from the Wikipedia entry, industrial smoke detectors were first on sale for commercial buildings in 1968. Domestic smoke alarms took longer to arrive, because they needed to be made more cost-effective.

Since the series is set from 1960 to 1970, and this episode is from season 1, these cannot be smoke detectors.

Fire detection alarms (often based on melting wax plugs, a simple but effective method which is still widely used today) have been available for much longer, of course. These could be what are depicted here. They are clearly not sprinklers, because sprinklers need to spray over a wider area.

More likely though, they could simply be air-con return vents. Air would be drawn in through those smaller vents, and circulated around the room through the larger directional vents. For an office where these simply carry out air circulation without cooling, there is no need to have these separated.

Improve this answer
1
  • 1
    Recessed sprinklers stay in the ceiling until heat melts/weakens something holding them up, then they drop down to look like regular sprinklers that give good coverage. Those seem like weird places for air return too. One is right next to a supply, it would just be dumping supply air right back out of the room. They look quite small for return vents too.
    – JMac
    Commented Dec 15 at 18:55

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .