CO2 Alarms/Detectors

Discussion in 'HVAC Heating & Cooling' started by chefwong, Jun 18, 2011.

  1. chefwong

    chefwong New Member

    Messages:
    710
    Location:
    District of Columbia
    Just came across this video.
    How much *truth* is in this when looking at a low level CO2 sensor vs. a regular unit.
    I have at least 1 BRK Hardwired Sensor in each area where we have gas sources.....and this video makes them look pretty useless ......

    http://www.youtube.com/watch?v=2M28lRzyEcI
  2. LLigetfa

    LLigetfa DIYer, not in the trades

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    3,989
    Location:
    NW Ontario, Canada
  3. jimbo

    jimbo Plumber

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    8,997
    Location:
    San Diego
    The scamster is completely oblivious to NFPA specs on CO alarms:

    1. At less than 30 ppm, it SHALL NOT alarm
    2. At 30 ppm continuous for 30 days, it SHALL NOT alarm
    3. At 400 ppm, it SHALL ALARM in 4 to 15 minutes
    4. At 150 ppm, it SHALL ALARM in 10 to 50 minutes
    5. At 70 ppm, it SHALL ALARM in 60 to 240 minutes

    Note that at the various levels, it shoulD NOT alarm in LESS than the lower time limit.

    CO is not a 'drop deap right now' killer. The ideas is to know about it, open the windows and get out in orderly fashion. His idea would lead to countless 'false alarms', unnecessary 911 calls, and removal of the battery by pissed off tenants.

    Early in the nuclear submarine error, the US Navy spec for CO was 50 ppm. The atmosphere in the boat typically ran in the 30 to 40's range, because that is the best the equipment could do at the time. They figured out that continuous at the 40+ range caused some headaches, etc. Fortunately by the time I started spending 275 days a year underwater, we had newer CO burners which could maintain a level of 25 ppm max, and we averaged aroung 15. No worries mate.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    22,019
    Location:
    New England
    Depending on your health, heart, and lung function, long exposures to lower levels of CO can compromise your health. Large concentrations can kill anyone. Some of the CO detectors available have a digital readout that shows the peak level in the last 'x' hours. Ideally, this is always reading zero. But, if you notice it creeping up, you have a problem that should be looked at somewhere.

    Awhile ago, I bought my sister one of these. They'd had it for a month or so, and then noticed the readout was non-zero and rising. Turns out, their furnace had about croaked (rusted heat exchanger on a forced-air system)...without the thing, they might not have known. This gave them a wake-up call before it was lethal that they needed to do something.

    Having one that just tells you you might die if you ignore it is handy, but I think those with a readout to tell you how bad it is are better. The things don't last forever, and should be replaced at the manufacturer's stated intervals to ensure they still work reliably. Same for smoke detectors...the recommendation is replace them at 10-year intervals to maintain reliability and take advantage of any new technologies.

    Way back when, these things were sometimes known for false alarming...now, that was very annoying. Don't think that is a current problem.
  5. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego

    My point is the he introduced about 50 ppm and expected it to alarm right away, which would in fact violate the ANSI/NFPA spec for these products.

    Most of the CO alarms I have come across recently have a 7 year timer....7 years from the first time the battery is installed, they start beeping and don't stop. Have to be replaced. The electo-chemical sensor is deemed to not be reliable beyond that point, so they literally time themselves out.
  6. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,154
    Location:
    Houston, TX
    The one other unit with a meter reading, did read the level, bet never alarmed.

    But the ones with the readout are the ones to buy, if you can afford them.

    What ever happened to the radon detectors ? They had everyone scared for nothing, I think.

    Same as for CO...

    If People are worried about CO then they should not drive a car or bike , or live in a big city.


    DonL


    P.S. Radon detectors may become popular again after what happened in Japan.
    But Japan can not make them now...
    Last edited: Jun 18, 2011
  7. jimbo

    jimbo Plumber

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    Location:
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    Radon is a serious issue IF you have it. It is long term exposure that is a problem, because we are never talking about levels that would be short-term hazardous. The best way to monitor radon is 30 day to six month tests.
  8. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,154
    Location:
    Houston, TX
    I bet that was of some concern on your sub.

    Most homes here do not have a problem, but people buy the detectors, just for grins.


    DonL
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,019
    Location:
    New England
    IMHO, anyone that has combustion appliances in their home should have at least one CO detector. If you lived a place like the Granite State (NH), radon would be more of an issue than in most sedimentary rock areas of Texas...most granite gives off at least a little radon, and if your home is built on rock, especially if they had to blast to level the site, you are at severe risk. There's more than one well that has problems as well, and requires special equipment to prevent the water from releasing radon gas into the home - particularly nasty if when you shower as you're then in a concentrated cloud of the stuff. The tighter the house, the worse it is.
  10. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
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    Even here in sunny San Diego, there is a death or near death every year, from a water heater or furnace issue, or running a barbecue grill or charcoal in the indoor fireplace.

    No radon on the boats. From the reactor, direct exposure to gamma rays when the teakettle is runnig full bore...can be a problem, but it is well shielded, and there are places you just don't go there. Of equal concern are the nuclear warheads, which we can neither confirm or deny that there was any such thing on board, which are sources of Neutron radiation, and in the case of casualty or failure....putonium ( beta ) and tritium.

    At one point, my daughter had a suspicion of radon based on a home 'quickie' test kit. After spending quite a bit on testing, we determined that the long term level was measureable but only around 2.5 picocuries, where the action level is >4 picocuries.

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