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PIRs for house with ceiling heating & cooling vents and "pets"!

Discussion in 'Security Alarms' started by eddy, Oct 24, 2007.

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  1. eddy

    eddy Guest

    I recently had an alarm system installed, consisting of a NX-16 panel,
    magnetic reeds on all doors and DSC encore PIRs in the main living
    areas. The PIRs, according to the installer are immune to small pets.
    In my case the pets consist of one 12kg Cavalier King charles spaniel
    who spends all his time sleeping and a 8kg, 15 year old cat who sleeps
    even more! Then there are the 2 Roomba discovery automatic vacuum
    cleaners, dinner plate size gadgets who run around the house at
    regular intervals sucking up debris.

    However, it was not this collection of pets who appear to have caused
    the problem. I also have heating and cooling ducts in the ceiling
    because the house is all on one level and built on a concrete slab. At
    the moment, because it's still early spring here, the heating
    occasionally comes on at 6.30pm. Because I sometimes get home only
    after 7.30pm, the heating has been running for around an hour. Over
    the last 8 weeks, practically every PIR in the house has falsed at
    least once after 6.30pm. Some of the heating ducts are within 3 ft of
    the PIR.

    To be absolutely sure, I have actually "banished" the pets from the
    house, but the false alarms still continue.

    To make matters worse, even if I did disable the timers that operate
    the thermostat, my heating unit is a ceiling mounted model which has a
    fan controller that is triggered by the ambient temperature inside the
    unit. In days that are hot enough, the heat in the roof is actually
    high enough to trick the fans into coming on, which in turns causes
    warm air to circulate into the house. And this has caused at least one
    false alarm ...

    In a situation like mine, are there PIRs which are capable of handling
    the disturbance from the heating ducts, or is the only option to have
    the PIRs removed from the security system ?

    rgds, Ed
  2. alarman

    alarman Guest

    The PIR's were installed (located) incorrectly by an inexperienced
    installer. They need to be relocated away from the heatong ducts, or at the
    least, replaced with dual-technology units. Who did the install?
  3. eddy

    eddy Guest

    Hi alarman,

    Yes, some of the PIRs are actually quite close to the heating ducts.
    The people who did the install are a Melbourne company called Insec
    security (Yes I am in Australia) . I have
    already called them. So hopefully they can do something. However, the
    guy I spoke to is trying to get me to accept that this is the way it
    is, and that I should never ever let my heating come on when the
    alarms are armed. If he is correct, I might have to get some highly
    paid heating technician or electrician to figure out how to ensure the
    heaters can be totally disabled!

    On the idea of dual tech PIRs, if I understand the theory correctly,
    is it because of the microwave element that this technology might be
    less vulnerable to alarming when the heaters come on?
  4. Nomen Nescio

    Nomen Nescio Guest

    Yes, some of the PIRs are actually quite close to the heating ducts.
    I concur with alarman; the motion detectors are not installed properly. As
    a general rule, you should not be able to feel any strong drafts at the
    motion detector, and this applies to dual tech units as well as to straight
    PIRs. Three feet away from a register is entirely too close. The solution
    is moving the units to a different location, not installing dual techs in
    the same bad locations. Your alarm company is probably loath to do this
    because it would mean running wire instead of just swapping equipment.

    It is your alarm company's job to provide you with a system that works
    reliably, not to tell you to turn off your heating system. If you aren't
    getting satisfaction from the people you are talking to, discuss your
    problem with the company's service manager.
  5. Kevin

    Kevin Guest

    I Have 5 DSC encore motion detectors installed on my premises. I have to
    say if installed properly they are very good units. In the 3 years my
    system has been in service I have not had any false alarms attributed to
    the motion detectors. In the interim maybe the system may be placed in
    cross zone or double hit mode if available to reduce the possibility of
    these false alarms.
  6. alarman

    alarman Guest

    Hi alarman,
    Yes, that's the idea.

    Oh, and your alarmco is full of shit. Get them to replace the PIR's they
    installed incorrectly, with dual-tech units, or move them. I lean toward the
    dual techs.
  7. alarman

    alarman Guest

    I used to use those when they were Detection Systems. They were not so hot.
    I am still replacing units with inoperative microwave components. DS knew
    about it, and shipped them anyway. We're done.
  8. Frank Olson

    Frank Olson Guest

    Have a look at the Paradox DG-75. They're an extremely stable PIR.
    IMHO, one of the best units out there.
  9. tourman

    tourman Guest

    RHC: Detection Systems for a long time shipped units out to the field
    with faulty microwave components AND THEY KNEW ABOUT IT...turned me
    right off !! However, the company was bought out by Bosch as I
    remember, and the new Bosch combination PIR and microwave units are
    splendid devices. As my standard motion, I have been using the Paradox
    DG 75 units, but lately, I have had a number of unexplainable failures
    which in several cases has caused me to eat false alarm fees. Near as
    I can tell, they either had a bad run of units, or perhaps they have
    shifted their production to China with the resulting cheapening of
    product quality...dunno. Mind you, I still use them in large
    quantities and I remain happy with them overall.

    DSC motions I won't touch at all....far too cheap and far too "hot"
    with a propensity to false alarm too easily given any environmental
  10. Frank Olson

    Frank Olson Guest

    Actually, I've had one Bravo 3 in my house for about a year now (OK,
    OK... I couldn't say "no" to Angela at Tried when she said "try one").
    Even with the stupid cat, I haven't had a single problem.
  11. tourman

    tourman Guest

    Actually, I've had one Bravo 3 in my house for about a year now (OK,
    RHC: Count your blessings then ! All these cheap little motions have
    no "forgiveness" built in.

    An analogy I use to explain motions to clients goes something like
    this. Think of a motion as a glass of water. A cheap motions is like a
    glass of water with the meniscus full, and even a slight jiggle or
    movement spills water from the glass. With the better motions,
    especially the dual techs, it's like a glass of water with the
    meniscus in a negative mode. You can jiggle it and nothing happens
    because there is some very little bit of space left in the glass But
    any real alarm is like hitting the glass with a hammer

    I know it's not a perfect analogy, but it works to explain the
    differences to non technical folks.
  12. tourman

    tourman Guest

    RHC: "Claculating".......

    Nah !....that was Professor B with his tinfoil suit who claimed to
    avoid detection by a motion detector. BTW, I wonder where our friend
    with the Loxxon alarm system is these days.
  13. Jim

    Jim Guest

    You have your "B's" mixed up.

    I don't think you were here when the original Professor B was.

    A whole other saga in the history of ASA.
  14. Jim

    Jim Guest

  15. eddy

    eddy Guest


    Update on the drama with my system. The company has agreed to replace
    the DSC pirs with Bosch Tritech units (They also call them blue line).
    The bad news ... they cost a lot more. Even if they are not charging
    me labour, its still working out to an additional AUD$660, thats 6
    units in total. As expected, the family are not supporting me on this
    one. Yes, I did complain and kick up a fuss, but they are standing
    firm on the fact that they are only charging me the difference in the
    cost of my originals and the new units. What I can't figure out is,
    pirs in general seem to cost a lot more here in Aus than say in the US
    or UK. I took a look at Bass's online store ... for 6 units, without
    shipping, it's still only a third of what I am spending here. I have
    called around a few other local companies, and they are all charging
    way above US rates, in fact the cost I got from my installer is
    cheap ... hmmm, maybe I should get them shipped from the US!!
  16. Frank Olson

    Frank Olson Guest

    That may seem like a good idea. The only thing is that you'll have to
    find a friendly local company to install them. You can try some of the
    online stores here:
  17. thesbian

    thesbian Guest

    either you have a HUGE house or you have too many motion sensors.
    eliminate all but a few 'critical' ones and live happily ever after.
  18. Nomen Nescio

    Nomen Nescio Guest

    eddy said:
    I've said this before, but it bears repeating:

    Don't automatically assume that all of your problems will be solved by
    installing dual technology detectors. Detector placement is extremely
    important for reliable performance, and dual technology is not a substitute
    for good installation practices.

    For example, I can think of a place that suddenly had LOTS of false alarms
    one night, even though dual tech sensors were in use. No previous
    problems. Turned out they had just gotten a new space heater (a big one,
    with a fan that blew hot air directly at the detector every twenty seconds
    or so). You could stand there and watch the unit trip when the hot air hit
    it! That's an extreme case, and the fan was blowing very hard, even though
    it was ten feet away.

    The point being, first install the detectors in the proper locations. Dual
    technology is a good idea, but it's not a cure-all.

    - badenov
  19. Frank Olson

    Frank Olson Guest

    They're actually running a fishing guide service in the Amazon. They
    started out by selling "boat anchors".
  20. Frank Olson

    Frank Olson Guest

    Serves them right!
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