Robert Green
24-01-2005, 11:04 AM
<ROBERT_GREEN1963@YAH00.COM> wrote:
(For anyone who's not familiar with Usenet’s quote nesting conventions, when
you see an even # of >'s (or none) those will be my (RG's) words, and an odd
number of >'s will indicate Mr. Butler's comments – I don’t want anyone to
think I’m trying to put words in anyone’s mouth)
>> "what are the effects of an accidental
>> activation of a whole house fan while the windows are closed?"
>
> OK, so for this new topic and question...
>
>
>>>My house leaks like a sieve, and I know I'm not alone in that.
>> . . . Clearly not *everyone's* house leaks like a sieve. Some
>> are so tight they need forced fresh air to a maintain good air quality.
>> Lots of houses in the north are *very* tightly sealed.
>
> Yup. And in those houses, the whole house fan will act EXACTLY like
> the forced ventilation.
Which is great, unless your whole house fan is active when there’s a fire or
a CO leak when the windows are closed. In a tightly-sealed house even a
passive attic vent can cause backdrafting. Older gas furnaces and water
heaters will happily vent into the living space if the pressure differential
is too high. A homeowner, having the latest and most well-inspected and
up-to-code appliances with CO detectors in key locations might be immune,
but many, many are not.
> After all, that is EXACTLY what the forced
> ventilation does -- evacuate air from the house so fresh will be drawn
> in (hopefully thru an air-2-air heat exchanger but not always).
Problems like the one I experienced usually occur in fall when the homeowner
first closes all the windows, fires up the furnace and accidentally triggers
or forgets about the whole house fan. Tight house, windows closed, CO-laden
air being sucked back down the chimney because burners perform inefficiently
when fed oxygen through their exhaust stack. The article at:
http://hem.dis.anl.gov/eehem/95/951103.html
reports anecdotal cases of combustion safety problems, including a Colorado
family of three who died from carbon monoxide poisoning when an attic
ventilator caused the furnace to backdraft. It happens to people every
year.
If it weren't a problem, it's hard to see Professor Tsongas spending so much
time and detail explaining how and why it happens and how to prevent it. If
it weren't a problem, you wouldn't see new furnaces designed with so many
safety interlocks to prevent it. If it weren’t a problem, CO wouldn’t be
the leading cause of poisoning deaths.
In this “alternate forced ventilation” failure mode you’re envisioning,
Sylvan, do you believe that a WHF will also suck enough fresh air in as well
as CO backdraft that lethal concentrations won't develop? That's a bet I
wouldn't want to take. The mechanisms for accidental intake of CO seem
pretty well known to HVAC engineers.
> > http://hem.dis.anl.gov/eehem/93/930309.html
>
> Yup, very familar with the topic.
If so, you should be well aware of the numerous cases of ventilators causing
lethal backdrafts, both from furnaces and garages where cars were left
idling. Most people don’t realize that any combustion device that can
generate CO creates increasingly more lethal concentrations of CO if it
aspirates its own oxygen-deprived exhaust.
In one of the many interesting case histories to be found at the DOE’s
Argonne National Laboratory site:
http://hem.dis.anl.gov/eehem/97/970509.html#97050901
they spell out *exactly* what problems an automatic attic fan can cause with
actual measurements of the pressure differentials:
"The real source of the problem was eventually found to be a 14-inch
roof-mounted attic fan. It operated automatically.(using a temperature
sensor) and would sometimes run for weeks at a time to reduce attic heat in
summer. When the fan operated, the basement was depressurized to 15 Pa (see
"Drawbacks of Powered Attic Ventilators," HE Nov/Dec '95, p. 5). This was an
older one-and-a-half story house that had many leaks connecting the basement
to the attic. In addition, the homeowner had recently put new steel siding
on the house, and the installers had blocked over the end gable vents and
the soffit vents, replacing them with much smaller and less effective
venting. Shutting off the fan in the attic decreased depressurization to 3
Pa. While the problem was originally thought to lie with the old furnace, in
the end, simply shutting off this fan solved the problem. (Thomas H. Greiner
is an associate professor of agriculture and biosystems engineering at Iowa
State University Extension)"
Professor Greiner goes on to say: "Too often people think that CO poisoning
cannot happen to them, because they live in a drafty older house or have a
new furnace. This is not true. As these cases reveal, CO poisoning can occur
in older, loose houses or newer, tight houses and can be caused by new
furnaces as well as old ones."
These aren't mere nuisance problems, they are problems that kill and maim
people for life. A little more digging brought me to Kidde's site:
http://www.kiddeus.com/NewsStatistics.shtml
"Carbon monoxide (CO) is the number one cause of poisoning deaths in the
United States. According to the Journal of the American Medical Association,
"there are approximately 2,100 unintentional deaths from carbon monoxide
(CO) every year in the U.S. and the use of CO Alarms could potentially
prevent many of these fatalities." In addition, more than 10,000 CO injuries
occur annually from this colorless, odorless and tasteless poison."
OK - now we're dealing with the number one cause of poisoning deaths in the
US. We're also dealing with 2,100 deaths and over 10,000 injuries. It's hard
to say exactly how many die because of many different factors and different
ways of counting, but there's no dispute that Americans are dying and that
many more are suffering serious ill effects from non-lethal poisonings. In
fact, deaths from indoor generator use doubled in 2003, according to the
CPSC.
>> exhaust devices can cause so much depressurization inside the
>> house that the normal chimney or flue flow of combustion
>> products from furnaces and water heaters reverses. This can
>> cause minor moisture damage or even death.
>
> Hey, look!!! Did you happen to notice another requirement? "combustion
> products". OK, I forgot that one, but it is another "must have" before
> your problem can occur. And of course it implies a <90% efficient
> system, or a critical malfunction in a >90% sealed combustion system.
D'oh! Sylvan, it's pretty darn impossible to even be *talking* about CO
poisoning without the assumption that a CO producing device is involved. Of
COURSE there's some sort of combustion system involved. Based on the over
12,000 deaths and injuries from CO a year JAMA/Kidde reports, it's not hard
to make a cognitive leap and assume that not everyone has an efficient
combustion system. All you need is an old one and some way to prevent the CO
from going up the flue and out of the house. The articles I've quoted makes
it pretty clear it's all-too-easy to negatively affect the drafting in a
house.
The table in the article at:
http://hem.dis.anl.gov/eehem/95/950308.html
gives the result of Combustion Safety Problems for 1,000 units tested by the
others. Lots of homes have serious problems with combustion appliances and
associated venting.
>> Back to the original topic. With so many people in the world both
>> using X-10 and dying yearly from CO poisoning,
>
> "so many"??? "in the world"???
12,000+ Americans are killed or injured by CO each year, according to
Kidde/JAMA. The Kidde site also claimed that CO poisoning is the number one
cause of poisoning deaths in the US. It's sad that does not impress you. Try
counting up all the names on your Rolodex and tell us how many times you
would have to multiply it to reach 12,000. That's a lot of people with brain
damage, lung damage and just plain old death damage to contend with.
> How many people using X10? 1% of the people in the world? No way.
That would be about 64 million people. I doubt if there are that many X-10
users. But a million wouldn’t surprise me with a revenue of $40+ million
between 1996-2000, according to this X-10 SEC filing:
http://www.sec.gov/Archives/edgar/data/1116262/000103221000500054/ds1a.txt
X-10 reported FY2000 revenue of $21,322,000. Now that was a year 2000 filing
and the growth rate that preceded it was phenomenal (stated in 1,000s):
1997 1998 1999 2000
$ 134 $ 2,997 $ 15,893 $ 21,322
I leave it to you to extrapolate how much X-10 gear is sold yearly. But
keep in mind those numbers represent only 1/5 of the time that X-10, BSR,
Smartlinc, Radio Shack, GE, Leviton and others were selling X-10 gear. I
wouldn't be surprised if the total isn't closer to $100 million dollars in
sales of X-10 compatible gear worldwide since X-10's inception.
> 1% of the "1st world"? Not likely (since home depot and lowes have both
> quit carrying it after short trial periods).
Probably because, like me, they realized the product liability potential.
Under US law, they would have co-defendants along with X-10 if there was a
product liability suit. Interestingly enough, X-10’s SEC filing addresses
your question about the proliferation or lack thereof of X-10:
"From inception [1997 for the WWW spin-off] through September 30, 2000,
we had $1.2 million in net revenues from sales through X10 Ltd. to sellers
of
customized, bundled or private-label versions of products and approximately
$1.0 million in net revenues from sales to retailers through X-10 (USA)."
$1,000,000 in re-badged products during four years is a lot of X-10 gear
considered it represents their wholesale cost per module. If you peg module
cost at a high average of $10 - that's 100,000 X-10 modules floating around.
Change that number to $2 a module (a much more likely wholesale price) and
it's 500,000 modules that have been rebadged. The claim against X-10 for
"pop-under" infringement was $4.3 million in compensatory damages was
upheld, although X-10 itself filed for bankruptcy. The over $450K awarded
in lost commissions ought to give some idea of the respectable size of the
X-10 distribution chain.
> Some miniscule fraction of the 1st world.
Based on the sales numbers I see and the number of companies that have sold,
are selling and will sell X-10 compatible gear, I’d peg that "miniscule
fraction" at 100,000 users at least, perhaps as many a million.
> How many do anything significant like controlling a
> whole-house fan? How about anything more significant than what they
> could have just done with a Clapper(tm)? 0.1% of industrialized world?
> I don't think so. 0.01%? Even that is probably high.
I know that my logic is often difficult for you to follow. I'm also aware
from your previous remarks that you do not consider logical extrapolation as
proof, so I am going to make this simple by resorting to anecdotal evidence.
Let's punch the words "X-10 Whole House Fan" into Google:
http://www.google.com/search?q=x-10+whole+house+fan
Very first hit:
Quiet Cool Whole House Fans - Installs in your attic... in whole house fan
products. The Quiet Cool fans can be controlled individually or multiple
fans can be wired to a single wall switch, timer or X-10 remote ...
www.quietcoolfan.com/ - 43k - Dec 29, 2004
Google lists 41,900 hits. While I'm sure they don't all concern X-10 and
WHFs, there are still plenty of solid hits to go around. Even you will have
to admit that it is sounding less and less like the OP and I are the only
ones in the world who ever put a whole house fan on X-10. It's just not
that unusual an application for X-10, as Google reveals.
Here's another hit, from the very first search page:
Tamarack Technologies, Inc. VTS Exhibit at the Builders' Virtual ......
Based on whole house fan concepts, they fit between 16 or 24 inch on
center
... The HV1000 is also available prewired for X10 whole house automation
www.buildersshow.com/bsn/vbooths.pl?masid=007408076-1 - 8k - Similar
pages
Whole house fans, pre-wired for X-10. Everywhere you look. It’s a fairly
natural use for X-10, since the fan is usually not located near the switch
that turns it on and fans are often added long after the house was built.
I punched the same search into Google, but this time into the Groups engine:
http://groups-beta.google.com/groups?q=x-10+whole+house+fan&hl=en&lr=&safe=o
ff&sa=N&tab=wg
and got 334 hits, the first being:
whole house fan- what x-10 switch?
I need to control (via X-10) a whole house fan. It is a simple on/off
circuit and doesn't draw more than 100watts. What is the best swich to
use? ...
comp.home.automation - Jun 28 1999, 8:52 am by Staff - 2 messages – 2
authors
There are hundreds more. So, it seems there are lots and lots of people
doing exactly what the OP and I are doing, and you can find them for
yourself, if you care to take the effort to do so.
> How many dying from CO poisoning yearly? 1%? 0.1%? 0.01%? That would
> be 0.0001, or from a city of 500,000 every year 50 would die from CO.
> Not even. Maybe 0.0001%.
Count the number of people you send Christmas cards to and imagine them all
dead from CO if you're tempted to think that 50 dead people is trivial
number.
> Do you really want to consider the entire world?
I don't have to. Google alone reveals 100's of people using X-10 to control
whole house fans. I'm not sure why that seems so incredible to you, but it's
right out there for anyone to see, using the same links I posted. It’s not
an esoteric use by any means, especially considering what things CHA posters
have tried to automate in the past.
> > X-10's statistically likely to be a
> > player in at least one of the deaths.
>
> So what.
So WHAT? SO WHAT???!!! That’s the WHOLE premise of this thread – that
someone’s already been killed through an accidental activation of X-10.
This is getting rather pointless, Sylvan. In fact, the only reason I’ve
bothered to continue is that I think that everyone here could learn
something by reading through the articles at the DOE/Argonne labs site. I
know I did.
>Unless you are reverting your premise above by saying home automation is
again a requirement?
I really have a very simple point: Putting a device like a whole house fan
on X-10 is asking for trouble. I'm not sure if you disagree with that, or
disagree with the fact that people DO put powered ventilators on X-10.
There are too many ways X-10 and ventilators can go wrong and suck fatal CO
back into the house from gas appliances and fireplaces. It can also cause a
tremendous acceleration in the spread of a fire. The bottom line is that
whole house fans should NOT be placed on X-10 unless you're VERY sure that
accidental activation is not going to suck exhaust gases back *down* the
chimney and into the house or accelerate the spread of flames if a fire
breaks out. From what I’ve read while researching this post, the only way
to be sure that won’t happen is to eliminate accidental activations of the
fan. Why is that such a tough concept?
If the numbers I’ve researched are correct, 20,000 Americans have died from
CO in the last 20 years. Many thousands more have died in fires. The
likelihood of an intersection between such large subsets and X-10 users is
pretty high. The propensity of many X-10’ers to modify dangerous equipment
makes them more likely to be in a pool of people who were killed by CO
poisoning or fires caused by an equipment malfunction. Suzy Sweater Knitter
is not going to burn a hole in her heat exchanger by modifying her furnace
electronics to short cycle the burner and build up condensation. Joe X-10
is a much more likely candidate for that simply based on the historically
dangerous uses for X-10 that I’ve presented repeatedly.
> [totally illogical and unfocused diatribe snipped]
I find it’s one thing to label something illogical but it’s quite another to
demonstrate it. I see you’ve chosen , once again, to have us take you at
your word, without any examples or references given about precisely *what*
was illogical.
Obviously you were unable to make the connection between the traits of the
average X-10 experimenter and how those traits would put them in a higher
risk pool. <sigh> For some reason I think you’re hung up on a belief that
my saying “at least ONE person has died from an X-10 related accident”
somehow translates into my believing that X-10 is as dangerous as a troop of
monkeys with guns or those recalled Firestone/Explorer tires and should be
banned. That’s not what I have been saying. Go back and read the first
post I made in the thread. BTW, “diatribe” means “a bitter and abusive
speech or writing.” It’s probably not *quite* the word you were looking
for. “Screed” would be a little closer to what I think you were trying to
say since it means “a lengthy discourse or an informal piece of writing.”
Let me try restating the point you apparently missed a bit more concisely.
We have a relatively broad sample of X-10 users in CHA. If you read through
the group or the archives you know that many of those users interconnect
X-10 with some pretty lethal stuff. They have hacked gas fireplaces,
external heaters, furnaces, thermostats, water heaters, space heaters,
industrial process equipment (yikes!), automobiles, hot tubs, irrigation,
outdoor Christmas lights, power windows, power TV lifts, drapes, automatic
garage doors and other equipment of varying danger potential.
We see less frequently, but fairly often, people posting who don't know
neutral from ground or what color the hot wire is supposed to be gleefully
wiring nutting one wire after another to find a combination that works.
Those two traits, when combined, increase the probability that there will be
trouble, maybe even lethal trouble. Joe X-10 is going to get into more
electrical and HVAC trouble than Jane Snap Switch. Why? Because X-10 is
susceptible to phantom signals and “click” type switches or hardwired
connections are not. More clear this time?
Let's try it another way, in case that was still too diffuse: People who
attach things to systems never designed to have things attached them are
more likely to get into trouble than people who make no modifications.
That's just the nature of complex systems and their interactions. Any time
you modify a system like a home's HVAC plant, especially using a technology
that responds to accidental activations as X-10 does, you're going to have
more accidents than in a system with no demonstrable history of false
activations. Why is this important? Because it defines a population a lot
more likely to end up intersecting with the population of people killed in
fires or by CO gas.
This is all mathematically provable, FWIW. People spend lifetimes trying to
perfect complex system design axioms. I have a logistician friend who could
bore us to tears explaining it all with fault trees and reliability block
diagrams but it's really rather commonsensical. The more ways there are to
trip a switch, the more likely it will be tripped accidentally. CM11A cable
dangling? Collisions? Neighbors? PalmPad slide switch set wrong? Power line
blip? Repeater gone psychotic? Book leaning on a MAXI 16 key? These are all
conditions that can cause an unintentional activation of X-10 or block PLC
signals. It’s nothing but a nuisance with light switches but once you
interlink X-10 with any of the combustion systems in your house the stakes
become quite a bit higher. Want a really foolproof home security system?
Hardwiring required. WHFs need to be hardwired as well because so much can
depend on their proper activation and deactivation. Is that succinct
enough?
>> I think it's just the sheer weight of numbers that says someone's
>> already extinguished themselves with the help of X-10.
>
>> It's just not realistic to think that X-10's been a death-free
technology.
>
> And nobody I've seen has claimed that.
Er, um, a, you kinda sorta did, on Dec. 26th when you wrote:
> And then how often would death result? It's going to be miniscule. One
> person? You're certain? I'm skeptical.
So, what, exactly then, are you arguing? That no one could possibly have
been killed by X-10 running a whole house fan with the windows shut and the
furnace on but they could have died from some other X-10 related issue?
> Your use of strawman argument is incredible.
It’s hardly any more incredible than your backing up your guesstimates with,
well, nothing.
> Do you believe or intend
> your deluge of poorly connected or totally unconnected reference and
> quotation to actually establish anything related to your original claim
> of automated whole house fan causing CO asphyxiation? How about at
> least the question with which you began this post?
At least I’m attempting to bring more to the table than simple opinion and
“hunches.” How about posting some verifiable facts of your own if you are
having so much trouble seeing the relevance of the ones I’ve provided? I
don’t recall seeing you provide a single reference to ANY data source other
than your own rather wide guesses about the probable size of the populations
under discussion.
I’m pretty confident that most people reading this will have far less
trouble than you're appearing to have connecting the dots. They're aware
that it is unlikely we would hear anything about even 10 people dying if it
were directly attributable to X-10. Other readers just might understand
that given:
a) the reliability problems of X-10
b) the DIY electricians of questionable skill that often link dangerous
equipment to X-10
c) the number of people who die from CO (2K) poisoning and in house fires
(5K) each year
d) the amount of X-10 gear sold yearly (>$22M in FY2000)
an intersection of those populations is not, as you first posited, a
completely unlikely event.
> As per the original contention, it still looks like the odds are slim
> that anyone has CO-snuffed themselves with an automated whole-house fan.
Actually, if you scroll back the beginning of this thread, sometime in
November, it began like this:
RG>> I'd wonder if there's any documented situations where amateur
automation was
>> shown to be a problem?
SB> Given the relative numbers, I'd guess the odds are pretty low.
As I noted before, we’ve wandered quite a bit away from “amateur automation
was shown to be a problem.” I stand by my original assertion that X-10 is
likely to have killed someone by now because we have a better idea of what
the relative numbers *really* are (even though my original remarks have been
hammered so far out of shape that we’re discussing something else).
We've also seen remarks from Professors Tsongas and Greiner, who
unequivocally state that death can result from exhaust fan problems. Any
month you choose at: http://hem.dis.anl.gov/eehem/hem_toc.html is bound to
be informative. One article describes how easily CO can be pulled into the
house from a garage because of the depressurization caused by an attic
ventilator. It took that poor homeowner 6 visits from assorted HVAC pros
and factory reps before a specialist she hired stripped the unit completely
and found a finger-sized hole in a heat exchanger that was leaking CO and
black soot into the house.
Another article at: http://hem.dis.anl.gov/eehem/01/010116.html
gives some very valuable insight how recessed “can” lights can open up
numerous air paths to attic. If citations like this seem too disjointed to
be relevant to you, consider how 16 extra chimneys in the attic are going to
help a whole house fan draw CO or fire directly through the bedrooms below
the attic. In case I need to explain it again, combustion appliances are
dangerous to begin with. Adding controls that can activate randomly only
makes disaster a more likely outcome.
After reading through article after article I'm more convinced than ever:
Adding X-10 to HVAC for anything but thermostat control is *very* unwise. If
a homeowner uses anything BUT a standalone, quality alarm/HA panel with
hardwires and lots of thoroughly tested safety interlocks for their power
ventilation, they are courting disaster. You don’t want an X-10 controlled
fan that is capable of sucking CO or flames up through the house. X-10 is
too unreliable for mission-critical systems. X-10 is wonderful for turning
off lights. I couldn’t imagine living without it. But it’s not so good for
ventilators or anything that can impact human safety.
I’ve said that about as many ways as I know how. If you still can’t follow
the logic, that’s a shame. As for who I’m going to believe: Why should
anyone believe two University engineering professors at different schools
who have published numerous papers on the subject at a DOE site when we have
you and your years of observation and keen statistical sixth sense? <g>
X-10 has been out on the market for 20 years selling over well over $40
million of gear. We've had, given various estimates, anywhere from 20,000 to
40,000 people that died in that same time from CO poisoning and 100,000
people die in fires. I'm not sure I'd be comfortable saying there is no
intersection in those populations. After all, who'd think someone could kill
themselves with a Lava lamp?
> > It took nearly 100 fatalities before the faulty tires on the Ford
> > Explorer became common knowledge.
>
> I would say "It took only 100 fatalities..."
I guess we have a philosophical difference on the meaning of 100 dead
people. <double sigh>
> And that was over a period
> of what, 5 years? 10 years? How many million tires on those Fords?
> X10 has been around for 25 years and how many million modules now? So
> where are the deaths????
Obviously you're not really reading much of what I am posting. No one's
claiming that X-10 is a ravenously murderous product, killing people like
Freddy Kruger on a par with faulty SUV tires or neck-breaking airbags. I
simply said that from my own experience it's pretty easy to activate a whole
house fan connected via X-10 accidentally and suck poisonous CO or flames
into your house. So easy, in fact, that an accidental whole house fan
activation has probably contributed to at least one death.
It's important to note *again* that death could be caused either by CO or by
a whole house fan's ability to feed a fire with perhaps 3 to 10 times the
amount of air it would normally get. Sort of like turning your house into a
convection oven if the fire starts in a place where the fan could really
feed it. Would you want your kids running down a staircase while a whole
house fan was pulling flames up the stairs to meet them? I wouldn’t. That’
s why my fan will be hardwired by the time summer rolls around. It’s too
risky to leave it on X-10.
Tennis star Vitas Gerulaitis, would be alive today if a faulty pool heater
had not caused seepage of lethal CO fumes into his home.
> > [Why that's *so* damn long I'll have to copyright it!]
> > Copyright 2004 Robert E. Green
>
> There are two disconnects in that strange bit of illogic...
>
> 1) Merely authoring your compilation grants copyright.
>
> 2) You posted your article on usenet. Usenet is a distributed system
> of autonomous nodes which by design automatically replicate and
> distribute your article. Your posting is an explict grant of license
> for others to copy and distribute your work. Oh, and usenet has no
> error detection much less error correction in replication/distribution.
It was mostly a test of your sense of humor and eagerness to correct people
loosely based on previous exchanges on the subject. I got exactly the
reading I expected. :-)
However, now that you’ve posted your opinion, I feel constrained to point
out that many people do not believe what you believe. A copyright notice
notably strengthens copyright protection. Were someone to re-post my
message, not on Usenet but on their website and I saw it, the copyright
notice would enable me to ensure their ISP made them take it down purdy damn
quick if I, the copyright holder, so chose.
ISPs in the US, at least, take the DMCA quite seriously. The explicit
notice makes it much harder for an infringer to mount any kind of
affirmative defense in appropriating the copyright. Putting the notice also
makes it clear that the author has no intention of placing message in the
public domain by posting on Usenet. Since you've taken a number of
opportunities to accuse me of using disjointed logic, what on earth does
Usenet error detection have to do with my placing a copyright notice on my
message? It’s a non sequitur.
A person much more knowledgeable than I about copyrights wrote:
"Some argue that posting to Usenet implicitly grants permission to everybody
to copy the posting within fairly wide bounds, and others feel that Usenet
is an automatic store and forward network where all the thousands of copies
made are done at the command (rather than the consent) of the poster. This
is a matter of some debate, but even if the former is true (and in this
writer's opinion we should all pray it isn't true) it simply would suggest
posters are implicitly granting permissions "for the sort of copying one
might expect when one posts to Usenet" and in no case is this a placement of
material into the public domain. It is important to remember that when it
comes to the law, computers never make copies, only human beings make
copies. Computers are given commands, not permission. Only people can be
given permission. Furthermore it is very difficult for an implicit license
to supersede an explicitly stated license that the copier was aware of."
You can read more at:
http://www.templetons.com/brad/copymyths.html
Bobby G.
Copyright 2005 by Robert E. Green :-)
(For anyone who's not familiar with Usenet’s quote nesting conventions, when
you see an even # of >'s (or none) those will be my (RG's) words, and an odd
number of >'s will indicate Mr. Butler's comments – I don’t want anyone to
think I’m trying to put words in anyone’s mouth)
>> "what are the effects of an accidental
>> activation of a whole house fan while the windows are closed?"
>
> OK, so for this new topic and question...
>
>
>>>My house leaks like a sieve, and I know I'm not alone in that.
>> . . . Clearly not *everyone's* house leaks like a sieve. Some
>> are so tight they need forced fresh air to a maintain good air quality.
>> Lots of houses in the north are *very* tightly sealed.
>
> Yup. And in those houses, the whole house fan will act EXACTLY like
> the forced ventilation.
Which is great, unless your whole house fan is active when there’s a fire or
a CO leak when the windows are closed. In a tightly-sealed house even a
passive attic vent can cause backdrafting. Older gas furnaces and water
heaters will happily vent into the living space if the pressure differential
is too high. A homeowner, having the latest and most well-inspected and
up-to-code appliances with CO detectors in key locations might be immune,
but many, many are not.
> After all, that is EXACTLY what the forced
> ventilation does -- evacuate air from the house so fresh will be drawn
> in (hopefully thru an air-2-air heat exchanger but not always).
Problems like the one I experienced usually occur in fall when the homeowner
first closes all the windows, fires up the furnace and accidentally triggers
or forgets about the whole house fan. Tight house, windows closed, CO-laden
air being sucked back down the chimney because burners perform inefficiently
when fed oxygen through their exhaust stack. The article at:
http://hem.dis.anl.gov/eehem/95/951103.html
reports anecdotal cases of combustion safety problems, including a Colorado
family of three who died from carbon monoxide poisoning when an attic
ventilator caused the furnace to backdraft. It happens to people every
year.
If it weren't a problem, it's hard to see Professor Tsongas spending so much
time and detail explaining how and why it happens and how to prevent it. If
it weren't a problem, you wouldn't see new furnaces designed with so many
safety interlocks to prevent it. If it weren’t a problem, CO wouldn’t be
the leading cause of poisoning deaths.
In this “alternate forced ventilation” failure mode you’re envisioning,
Sylvan, do you believe that a WHF will also suck enough fresh air in as well
as CO backdraft that lethal concentrations won't develop? That's a bet I
wouldn't want to take. The mechanisms for accidental intake of CO seem
pretty well known to HVAC engineers.
> > http://hem.dis.anl.gov/eehem/93/930309.html
>
> Yup, very familar with the topic.
If so, you should be well aware of the numerous cases of ventilators causing
lethal backdrafts, both from furnaces and garages where cars were left
idling. Most people don’t realize that any combustion device that can
generate CO creates increasingly more lethal concentrations of CO if it
aspirates its own oxygen-deprived exhaust.
In one of the many interesting case histories to be found at the DOE’s
Argonne National Laboratory site:
http://hem.dis.anl.gov/eehem/97/970509.html#97050901
they spell out *exactly* what problems an automatic attic fan can cause with
actual measurements of the pressure differentials:
"The real source of the problem was eventually found to be a 14-inch
roof-mounted attic fan. It operated automatically.(using a temperature
sensor) and would sometimes run for weeks at a time to reduce attic heat in
summer. When the fan operated, the basement was depressurized to 15 Pa (see
"Drawbacks of Powered Attic Ventilators," HE Nov/Dec '95, p. 5). This was an
older one-and-a-half story house that had many leaks connecting the basement
to the attic. In addition, the homeowner had recently put new steel siding
on the house, and the installers had blocked over the end gable vents and
the soffit vents, replacing them with much smaller and less effective
venting. Shutting off the fan in the attic decreased depressurization to 3
Pa. While the problem was originally thought to lie with the old furnace, in
the end, simply shutting off this fan solved the problem. (Thomas H. Greiner
is an associate professor of agriculture and biosystems engineering at Iowa
State University Extension)"
Professor Greiner goes on to say: "Too often people think that CO poisoning
cannot happen to them, because they live in a drafty older house or have a
new furnace. This is not true. As these cases reveal, CO poisoning can occur
in older, loose houses or newer, tight houses and can be caused by new
furnaces as well as old ones."
These aren't mere nuisance problems, they are problems that kill and maim
people for life. A little more digging brought me to Kidde's site:
http://www.kiddeus.com/NewsStatistics.shtml
"Carbon monoxide (CO) is the number one cause of poisoning deaths in the
United States. According to the Journal of the American Medical Association,
"there are approximately 2,100 unintentional deaths from carbon monoxide
(CO) every year in the U.S. and the use of CO Alarms could potentially
prevent many of these fatalities." In addition, more than 10,000 CO injuries
occur annually from this colorless, odorless and tasteless poison."
OK - now we're dealing with the number one cause of poisoning deaths in the
US. We're also dealing with 2,100 deaths and over 10,000 injuries. It's hard
to say exactly how many die because of many different factors and different
ways of counting, but there's no dispute that Americans are dying and that
many more are suffering serious ill effects from non-lethal poisonings. In
fact, deaths from indoor generator use doubled in 2003, according to the
CPSC.
>> exhaust devices can cause so much depressurization inside the
>> house that the normal chimney or flue flow of combustion
>> products from furnaces and water heaters reverses. This can
>> cause minor moisture damage or even death.
>
> Hey, look!!! Did you happen to notice another requirement? "combustion
> products". OK, I forgot that one, but it is another "must have" before
> your problem can occur. And of course it implies a <90% efficient
> system, or a critical malfunction in a >90% sealed combustion system.
D'oh! Sylvan, it's pretty darn impossible to even be *talking* about CO
poisoning without the assumption that a CO producing device is involved. Of
COURSE there's some sort of combustion system involved. Based on the over
12,000 deaths and injuries from CO a year JAMA/Kidde reports, it's not hard
to make a cognitive leap and assume that not everyone has an efficient
combustion system. All you need is an old one and some way to prevent the CO
from going up the flue and out of the house. The articles I've quoted makes
it pretty clear it's all-too-easy to negatively affect the drafting in a
house.
The table in the article at:
http://hem.dis.anl.gov/eehem/95/950308.html
gives the result of Combustion Safety Problems for 1,000 units tested by the
others. Lots of homes have serious problems with combustion appliances and
associated venting.
>> Back to the original topic. With so many people in the world both
>> using X-10 and dying yearly from CO poisoning,
>
> "so many"??? "in the world"???
12,000+ Americans are killed or injured by CO each year, according to
Kidde/JAMA. The Kidde site also claimed that CO poisoning is the number one
cause of poisoning deaths in the US. It's sad that does not impress you. Try
counting up all the names on your Rolodex and tell us how many times you
would have to multiply it to reach 12,000. That's a lot of people with brain
damage, lung damage and just plain old death damage to contend with.
> How many people using X10? 1% of the people in the world? No way.
That would be about 64 million people. I doubt if there are that many X-10
users. But a million wouldn’t surprise me with a revenue of $40+ million
between 1996-2000, according to this X-10 SEC filing:
http://www.sec.gov/Archives/edgar/data/1116262/000103221000500054/ds1a.txt
X-10 reported FY2000 revenue of $21,322,000. Now that was a year 2000 filing
and the growth rate that preceded it was phenomenal (stated in 1,000s):
1997 1998 1999 2000
$ 134 $ 2,997 $ 15,893 $ 21,322
I leave it to you to extrapolate how much X-10 gear is sold yearly. But
keep in mind those numbers represent only 1/5 of the time that X-10, BSR,
Smartlinc, Radio Shack, GE, Leviton and others were selling X-10 gear. I
wouldn't be surprised if the total isn't closer to $100 million dollars in
sales of X-10 compatible gear worldwide since X-10's inception.
> 1% of the "1st world"? Not likely (since home depot and lowes have both
> quit carrying it after short trial periods).
Probably because, like me, they realized the product liability potential.
Under US law, they would have co-defendants along with X-10 if there was a
product liability suit. Interestingly enough, X-10’s SEC filing addresses
your question about the proliferation or lack thereof of X-10:
"From inception [1997 for the WWW spin-off] through September 30, 2000,
we had $1.2 million in net revenues from sales through X10 Ltd. to sellers
of
customized, bundled or private-label versions of products and approximately
$1.0 million in net revenues from sales to retailers through X-10 (USA)."
$1,000,000 in re-badged products during four years is a lot of X-10 gear
considered it represents their wholesale cost per module. If you peg module
cost at a high average of $10 - that's 100,000 X-10 modules floating around.
Change that number to $2 a module (a much more likely wholesale price) and
it's 500,000 modules that have been rebadged. The claim against X-10 for
"pop-under" infringement was $4.3 million in compensatory damages was
upheld, although X-10 itself filed for bankruptcy. The over $450K awarded
in lost commissions ought to give some idea of the respectable size of the
X-10 distribution chain.
> Some miniscule fraction of the 1st world.
Based on the sales numbers I see and the number of companies that have sold,
are selling and will sell X-10 compatible gear, I’d peg that "miniscule
fraction" at 100,000 users at least, perhaps as many a million.
> How many do anything significant like controlling a
> whole-house fan? How about anything more significant than what they
> could have just done with a Clapper(tm)? 0.1% of industrialized world?
> I don't think so. 0.01%? Even that is probably high.
I know that my logic is often difficult for you to follow. I'm also aware
from your previous remarks that you do not consider logical extrapolation as
proof, so I am going to make this simple by resorting to anecdotal evidence.
Let's punch the words "X-10 Whole House Fan" into Google:
http://www.google.com/search?q=x-10+whole+house+fan
Very first hit:
Quiet Cool Whole House Fans - Installs in your attic... in whole house fan
products. The Quiet Cool fans can be controlled individually or multiple
fans can be wired to a single wall switch, timer or X-10 remote ...
www.quietcoolfan.com/ - 43k - Dec 29, 2004
Google lists 41,900 hits. While I'm sure they don't all concern X-10 and
WHFs, there are still plenty of solid hits to go around. Even you will have
to admit that it is sounding less and less like the OP and I are the only
ones in the world who ever put a whole house fan on X-10. It's just not
that unusual an application for X-10, as Google reveals.
Here's another hit, from the very first search page:
Tamarack Technologies, Inc. VTS Exhibit at the Builders' Virtual ......
Based on whole house fan concepts, they fit between 16 or 24 inch on
center
... The HV1000 is also available prewired for X10 whole house automation
www.buildersshow.com/bsn/vbooths.pl?masid=007408076-1 - 8k - Similar
pages
Whole house fans, pre-wired for X-10. Everywhere you look. It’s a fairly
natural use for X-10, since the fan is usually not located near the switch
that turns it on and fans are often added long after the house was built.
I punched the same search into Google, but this time into the Groups engine:
http://groups-beta.google.com/groups?q=x-10+whole+house+fan&hl=en&lr=&safe=o
ff&sa=N&tab=wg
and got 334 hits, the first being:
whole house fan- what x-10 switch?
I need to control (via X-10) a whole house fan. It is a simple on/off
circuit and doesn't draw more than 100watts. What is the best swich to
use? ...
comp.home.automation - Jun 28 1999, 8:52 am by Staff - 2 messages – 2
authors
There are hundreds more. So, it seems there are lots and lots of people
doing exactly what the OP and I are doing, and you can find them for
yourself, if you care to take the effort to do so.
> How many dying from CO poisoning yearly? 1%? 0.1%? 0.01%? That would
> be 0.0001, or from a city of 500,000 every year 50 would die from CO.
> Not even. Maybe 0.0001%.
Count the number of people you send Christmas cards to and imagine them all
dead from CO if you're tempted to think that 50 dead people is trivial
number.
> Do you really want to consider the entire world?
I don't have to. Google alone reveals 100's of people using X-10 to control
whole house fans. I'm not sure why that seems so incredible to you, but it's
right out there for anyone to see, using the same links I posted. It’s not
an esoteric use by any means, especially considering what things CHA posters
have tried to automate in the past.
> > X-10's statistically likely to be a
> > player in at least one of the deaths.
>
> So what.
So WHAT? SO WHAT???!!! That’s the WHOLE premise of this thread – that
someone’s already been killed through an accidental activation of X-10.
This is getting rather pointless, Sylvan. In fact, the only reason I’ve
bothered to continue is that I think that everyone here could learn
something by reading through the articles at the DOE/Argonne labs site. I
know I did.
>Unless you are reverting your premise above by saying home automation is
again a requirement?
I really have a very simple point: Putting a device like a whole house fan
on X-10 is asking for trouble. I'm not sure if you disagree with that, or
disagree with the fact that people DO put powered ventilators on X-10.
There are too many ways X-10 and ventilators can go wrong and suck fatal CO
back into the house from gas appliances and fireplaces. It can also cause a
tremendous acceleration in the spread of a fire. The bottom line is that
whole house fans should NOT be placed on X-10 unless you're VERY sure that
accidental activation is not going to suck exhaust gases back *down* the
chimney and into the house or accelerate the spread of flames if a fire
breaks out. From what I’ve read while researching this post, the only way
to be sure that won’t happen is to eliminate accidental activations of the
fan. Why is that such a tough concept?
If the numbers I’ve researched are correct, 20,000 Americans have died from
CO in the last 20 years. Many thousands more have died in fires. The
likelihood of an intersection between such large subsets and X-10 users is
pretty high. The propensity of many X-10’ers to modify dangerous equipment
makes them more likely to be in a pool of people who were killed by CO
poisoning or fires caused by an equipment malfunction. Suzy Sweater Knitter
is not going to burn a hole in her heat exchanger by modifying her furnace
electronics to short cycle the burner and build up condensation. Joe X-10
is a much more likely candidate for that simply based on the historically
dangerous uses for X-10 that I’ve presented repeatedly.
> [totally illogical and unfocused diatribe snipped]
I find it’s one thing to label something illogical but it’s quite another to
demonstrate it. I see you’ve chosen , once again, to have us take you at
your word, without any examples or references given about precisely *what*
was illogical.
Obviously you were unable to make the connection between the traits of the
average X-10 experimenter and how those traits would put them in a higher
risk pool. <sigh> For some reason I think you’re hung up on a belief that
my saying “at least ONE person has died from an X-10 related accident”
somehow translates into my believing that X-10 is as dangerous as a troop of
monkeys with guns or those recalled Firestone/Explorer tires and should be
banned. That’s not what I have been saying. Go back and read the first
post I made in the thread. BTW, “diatribe” means “a bitter and abusive
speech or writing.” It’s probably not *quite* the word you were looking
for. “Screed” would be a little closer to what I think you were trying to
say since it means “a lengthy discourse or an informal piece of writing.”
Let me try restating the point you apparently missed a bit more concisely.
We have a relatively broad sample of X-10 users in CHA. If you read through
the group or the archives you know that many of those users interconnect
X-10 with some pretty lethal stuff. They have hacked gas fireplaces,
external heaters, furnaces, thermostats, water heaters, space heaters,
industrial process equipment (yikes!), automobiles, hot tubs, irrigation,
outdoor Christmas lights, power windows, power TV lifts, drapes, automatic
garage doors and other equipment of varying danger potential.
We see less frequently, but fairly often, people posting who don't know
neutral from ground or what color the hot wire is supposed to be gleefully
wiring nutting one wire after another to find a combination that works.
Those two traits, when combined, increase the probability that there will be
trouble, maybe even lethal trouble. Joe X-10 is going to get into more
electrical and HVAC trouble than Jane Snap Switch. Why? Because X-10 is
susceptible to phantom signals and “click” type switches or hardwired
connections are not. More clear this time?
Let's try it another way, in case that was still too diffuse: People who
attach things to systems never designed to have things attached them are
more likely to get into trouble than people who make no modifications.
That's just the nature of complex systems and their interactions. Any time
you modify a system like a home's HVAC plant, especially using a technology
that responds to accidental activations as X-10 does, you're going to have
more accidents than in a system with no demonstrable history of false
activations. Why is this important? Because it defines a population a lot
more likely to end up intersecting with the population of people killed in
fires or by CO gas.
This is all mathematically provable, FWIW. People spend lifetimes trying to
perfect complex system design axioms. I have a logistician friend who could
bore us to tears explaining it all with fault trees and reliability block
diagrams but it's really rather commonsensical. The more ways there are to
trip a switch, the more likely it will be tripped accidentally. CM11A cable
dangling? Collisions? Neighbors? PalmPad slide switch set wrong? Power line
blip? Repeater gone psychotic? Book leaning on a MAXI 16 key? These are all
conditions that can cause an unintentional activation of X-10 or block PLC
signals. It’s nothing but a nuisance with light switches but once you
interlink X-10 with any of the combustion systems in your house the stakes
become quite a bit higher. Want a really foolproof home security system?
Hardwiring required. WHFs need to be hardwired as well because so much can
depend on their proper activation and deactivation. Is that succinct
enough?
>> I think it's just the sheer weight of numbers that says someone's
>> already extinguished themselves with the help of X-10.
>
>> It's just not realistic to think that X-10's been a death-free
technology.
>
> And nobody I've seen has claimed that.
Er, um, a, you kinda sorta did, on Dec. 26th when you wrote:
> And then how often would death result? It's going to be miniscule. One
> person? You're certain? I'm skeptical.
So, what, exactly then, are you arguing? That no one could possibly have
been killed by X-10 running a whole house fan with the windows shut and the
furnace on but they could have died from some other X-10 related issue?
> Your use of strawman argument is incredible.
It’s hardly any more incredible than your backing up your guesstimates with,
well, nothing.
> Do you believe or intend
> your deluge of poorly connected or totally unconnected reference and
> quotation to actually establish anything related to your original claim
> of automated whole house fan causing CO asphyxiation? How about at
> least the question with which you began this post?
At least I’m attempting to bring more to the table than simple opinion and
“hunches.” How about posting some verifiable facts of your own if you are
having so much trouble seeing the relevance of the ones I’ve provided? I
don’t recall seeing you provide a single reference to ANY data source other
than your own rather wide guesses about the probable size of the populations
under discussion.
I’m pretty confident that most people reading this will have far less
trouble than you're appearing to have connecting the dots. They're aware
that it is unlikely we would hear anything about even 10 people dying if it
were directly attributable to X-10. Other readers just might understand
that given:
a) the reliability problems of X-10
b) the DIY electricians of questionable skill that often link dangerous
equipment to X-10
c) the number of people who die from CO (2K) poisoning and in house fires
(5K) each year
d) the amount of X-10 gear sold yearly (>$22M in FY2000)
an intersection of those populations is not, as you first posited, a
completely unlikely event.
> As per the original contention, it still looks like the odds are slim
> that anyone has CO-snuffed themselves with an automated whole-house fan.
Actually, if you scroll back the beginning of this thread, sometime in
November, it began like this:
RG>> I'd wonder if there's any documented situations where amateur
automation was
>> shown to be a problem?
SB> Given the relative numbers, I'd guess the odds are pretty low.
As I noted before, we’ve wandered quite a bit away from “amateur automation
was shown to be a problem.” I stand by my original assertion that X-10 is
likely to have killed someone by now because we have a better idea of what
the relative numbers *really* are (even though my original remarks have been
hammered so far out of shape that we’re discussing something else).
We've also seen remarks from Professors Tsongas and Greiner, who
unequivocally state that death can result from exhaust fan problems. Any
month you choose at: http://hem.dis.anl.gov/eehem/hem_toc.html is bound to
be informative. One article describes how easily CO can be pulled into the
house from a garage because of the depressurization caused by an attic
ventilator. It took that poor homeowner 6 visits from assorted HVAC pros
and factory reps before a specialist she hired stripped the unit completely
and found a finger-sized hole in a heat exchanger that was leaking CO and
black soot into the house.
Another article at: http://hem.dis.anl.gov/eehem/01/010116.html
gives some very valuable insight how recessed “can” lights can open up
numerous air paths to attic. If citations like this seem too disjointed to
be relevant to you, consider how 16 extra chimneys in the attic are going to
help a whole house fan draw CO or fire directly through the bedrooms below
the attic. In case I need to explain it again, combustion appliances are
dangerous to begin with. Adding controls that can activate randomly only
makes disaster a more likely outcome.
After reading through article after article I'm more convinced than ever:
Adding X-10 to HVAC for anything but thermostat control is *very* unwise. If
a homeowner uses anything BUT a standalone, quality alarm/HA panel with
hardwires and lots of thoroughly tested safety interlocks for their power
ventilation, they are courting disaster. You don’t want an X-10 controlled
fan that is capable of sucking CO or flames up through the house. X-10 is
too unreliable for mission-critical systems. X-10 is wonderful for turning
off lights. I couldn’t imagine living without it. But it’s not so good for
ventilators or anything that can impact human safety.
I’ve said that about as many ways as I know how. If you still can’t follow
the logic, that’s a shame. As for who I’m going to believe: Why should
anyone believe two University engineering professors at different schools
who have published numerous papers on the subject at a DOE site when we have
you and your years of observation and keen statistical sixth sense? <g>
X-10 has been out on the market for 20 years selling over well over $40
million of gear. We've had, given various estimates, anywhere from 20,000 to
40,000 people that died in that same time from CO poisoning and 100,000
people die in fires. I'm not sure I'd be comfortable saying there is no
intersection in those populations. After all, who'd think someone could kill
themselves with a Lava lamp?
> > It took nearly 100 fatalities before the faulty tires on the Ford
> > Explorer became common knowledge.
>
> I would say "It took only 100 fatalities..."
I guess we have a philosophical difference on the meaning of 100 dead
people. <double sigh>
> And that was over a period
> of what, 5 years? 10 years? How many million tires on those Fords?
> X10 has been around for 25 years and how many million modules now? So
> where are the deaths????
Obviously you're not really reading much of what I am posting. No one's
claiming that X-10 is a ravenously murderous product, killing people like
Freddy Kruger on a par with faulty SUV tires or neck-breaking airbags. I
simply said that from my own experience it's pretty easy to activate a whole
house fan connected via X-10 accidentally and suck poisonous CO or flames
into your house. So easy, in fact, that an accidental whole house fan
activation has probably contributed to at least one death.
It's important to note *again* that death could be caused either by CO or by
a whole house fan's ability to feed a fire with perhaps 3 to 10 times the
amount of air it would normally get. Sort of like turning your house into a
convection oven if the fire starts in a place where the fan could really
feed it. Would you want your kids running down a staircase while a whole
house fan was pulling flames up the stairs to meet them? I wouldn’t. That’
s why my fan will be hardwired by the time summer rolls around. It’s too
risky to leave it on X-10.
Tennis star Vitas Gerulaitis, would be alive today if a faulty pool heater
had not caused seepage of lethal CO fumes into his home.
> > [Why that's *so* damn long I'll have to copyright it!]
> > Copyright 2004 Robert E. Green
>
> There are two disconnects in that strange bit of illogic...
>
> 1) Merely authoring your compilation grants copyright.
>
> 2) You posted your article on usenet. Usenet is a distributed system
> of autonomous nodes which by design automatically replicate and
> distribute your article. Your posting is an explict grant of license
> for others to copy and distribute your work. Oh, and usenet has no
> error detection much less error correction in replication/distribution.
It was mostly a test of your sense of humor and eagerness to correct people
loosely based on previous exchanges on the subject. I got exactly the
reading I expected. :-)
However, now that you’ve posted your opinion, I feel constrained to point
out that many people do not believe what you believe. A copyright notice
notably strengthens copyright protection. Were someone to re-post my
message, not on Usenet but on their website and I saw it, the copyright
notice would enable me to ensure their ISP made them take it down purdy damn
quick if I, the copyright holder, so chose.
ISPs in the US, at least, take the DMCA quite seriously. The explicit
notice makes it much harder for an infringer to mount any kind of
affirmative defense in appropriating the copyright. Putting the notice also
makes it clear that the author has no intention of placing message in the
public domain by posting on Usenet. Since you've taken a number of
opportunities to accuse me of using disjointed logic, what on earth does
Usenet error detection have to do with my placing a copyright notice on my
message? It’s a non sequitur.
A person much more knowledgeable than I about copyrights wrote:
"Some argue that posting to Usenet implicitly grants permission to everybody
to copy the posting within fairly wide bounds, and others feel that Usenet
is an automatic store and forward network where all the thousands of copies
made are done at the command (rather than the consent) of the poster. This
is a matter of some debate, but even if the former is true (and in this
writer's opinion we should all pray it isn't true) it simply would suggest
posters are implicitly granting permissions "for the sort of copying one
might expect when one posts to Usenet" and in no case is this a placement of
material into the public domain. It is important to remember that when it
comes to the law, computers never make copies, only human beings make
copies. Computers are given commands, not permission. Only people can be
given permission. Furthermore it is very difficult for an implicit license
to supersede an explicitly stated license that the copier was aware of."
You can read more at:
http://www.templetons.com/brad/copymyths.html
Bobby G.
Copyright 2005 by Robert E. Green :-)