On Thursday, October 1, 2015 at 10:26:59 PM UTC-4, Don Y wrote:
On 10/1/2015 5:36 PM, DerbyDad03 wrote:
On Thursday, October 1, 2015 at 3:47:16 PM UTC-4, Don Y wrote:
You said it's a common practice for people to leave the batteries out. I say
it's not "common" in relation to how many detectors there are installed across
the globe.
Whether the batteries are left out for a night, a day or a year before the
fatal fires starts has nothing to do with the commonality of the practice.
How often they are left out as compared how often they are not is all that
counts when determining how "common" the practice is.
From a 9/2015 NFPA report:
Smoke Alarm Power Sources
Hardwired smoke alarms were present in 48% of reported home fires with smoke
alarms. Alarms powered by battery only were present in in 46% of reported home
fires.
In reported home fires in which the fire was large enough to activate the
alarm,
- Hardwired smoke alarms operated 94% of the time.
- Battery-powered smoke alarms operated in four out of five (80%) fires.
Reasons that Smoke Alarms Did Not Operate when Present in Large Enough Fires
--------------------------^^^^^^^^^^^^^^^
In fires in which the smoke alarms were present but did not operate,
- Almost half (46%) of the smoke alarms had missing or disconnected
batteries. Nuisance alarms were the leading reason for disconnected
smoke alarms.
- Dead batteries caused one-quarter (24%) of the smoke alarm failures.
- Only 7% of the failures were due to hardwired power source problems,
including disconnected smoke alarms, power outages, and power shut-offs.
So, in response to your comment, below:
"Common? Until I see the numbers, I'll vote No."
I vote *yes* (70% of the fires!) -- unless you'd care to offer some OTHER
numbers?
Right, in 70% of homes *in which the smoke alarms were present but did not
operate* dead or missing batteries was the cause. No one denies that dead
or missing batteries will cause a smoke detector not to operate. The problem
is (once again) that that is not what we are discussing.
I'll try again: You said that the practice of leaving batteries out after
they are removed due to chirping is "common". I, once again, say that when
compared to all the cases where the batteries are *not* left out, the
practice is *not* common. The *practice of leaving the batteries out* is not
common. Does it happen? Yes. Do bad things happen when someone does that? Yes.
Is it common? Not in the grand scheme of all detectors everywhere.
Can you stick to that statement and tell me how you know that the practice is
common? Tell me how many times batteries are left out vs. how many times
they are replaced. Citing statistics related to how many smoke
detectors didn't operate due to missing batteries (46%) does nothing to
support your claim that the practice of leaving batteries out is "common". All
that does is tell us that missing batteries is a common cause for smoke
detectors not to operate. Well, yeah. I think that's pretty obvious.
It seems pretty obvious to me that the above statistic cites that 46% of those
FIRES had smoke detectors with batteries "missing or disconnected". Do you
think the "smoke detector police" are going to arbitrarily survey homes
where NO FIRES HAVE BEEN REPORTED to see if their smoke detectors have
batteries in place? If a battery is left out for a year (assume a battery
normally *lasts* a year, does that count as *one* event? Or, more than one?)
Thank you! You have finally made my point that the statistic you cited,
while true, does nothing to support your claim that leaving batteries
out is "common". That statistic is not relevant to this discussion. It
took us a while, but we're finally there.
Will the smoke detector police ensure that you *have* smoke detectors in
a residence if the residence is not offered for sale?
What criteria would you use to claim this practice was *RARE*? (!common)
Now, citing statistics that show 55% of the millions upon millions of smoke
detectors that needed batteries did not have them replaced would indeed
indicate that the practice of leaving the batteries out is common.
"Common" doesn't mean "in a majority of cases". Common means "of frequent
occurrence". "Daniel" is a "common" name. By no means are 50.0001% of
the people in the world/country named "Daniel". In fact, it is the
*10th* most common name in the US -- yet LESS THAN 1% of the population
having it! There are no names that rise to the "55% level" that you
seem to suggest would constitute 'common-ness'
That number was just an example to get you to understand that your 46%
statistic was not relevant. It was not the actual value (my fictitious 55%)
that matters. What matters is the comparison of detectors that didn't
operate because the batteries were left out to detectors that operated
properly plus those that didn't operate for other reasons.
You can't use a percentage of a subset to come to a conclusion about the
entire set unless you adjust the percentage to match the size of the subset
in relation to the entire set. (I'll do that below)
Why don't *you* come up with a criteria to indicate what *NUMBER* you
consider to be representative of the term "common". Then, *justify*
that number (in an OBJECTIVE sense).
You can start by obtaining NUMBERS for the actual number of
residences/occupancies that have/require smoke detectors, then
the number of smoke detectors currently deployed in those areas,
then, the NUMBER you would consider to be representative of
the adjective "COMMON".
It looks like you have finally gotten my point. Alleluia!
The following comment is paraphrased from:
http://www.nfpa.org/~/media/files/re...arms.pdf?la=en
"In fires considered large enough to trigger an alarm, battery-powered smoke detectors operated 80% of the time."
That leaves us with 20% of the installed battery-powered base that didn't
operate.
Paraphrasing your statistic from earlier:
"In fires in which the smoke alarms were present but did not operate, 46% of the smoke alarms had missing or disconnected batteries"
Doing the math and taking 46% of the 20% that didn't operate we end up with
9.2% of detectors involved with a fire that were disabled because the user
left the battery out. Even though we are still using a subset of all
installed detectors, I'm comfortable saying I wouldn't consider 9.2% to be
"common", even if that number applied to the entire installed base. But,
wait, there's more...
Those percentages only account for the detectors that were involved in a
fire. It's a safe assumption that the number of detectors *not* involved
in a fire is ridiculously huge compared to the number that were involved.
While I'm comfortable in saying that 9.2% is not "common", I'm just as
comfortable is saying that the percentage will get even smaller as the
sample size grows. I may be going way, way out on a limb here, and it's
nothing more than wild speculation on my part, but here's my theory on why
those numbers won't scale linearly:
I postulate that a fire is more apt to happen in a home where the residents
leave the batteries out than in a home where they are replaced promptly.
If I look at it from a "behavioral" perspective, I can imagine that, for the
most part, people that would leave the battery out have other dangerous
habits, maintenance issues, etc. In other words, there will be more fire
causing factors in those homes. Frayed extension cords, combustible
materials near the furnace, etc.
If that assumption is true, then the 9.2% is going to get even smaller
as we include more and more detectors from non-fire impacted residences.
In other words, we will move even farther away from the practice of leaving the batteries out as being "common".