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  Reply # 1592518 14-Jul-2016 14:15
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Well, given one of the Family Shield alarms was going off when I simply re-inserted the battery this would indicate a failure of either the "10 year" battery (that was two years old) or the unit itself, versus its placement or specifics of its location in our house. That said, the other one would go off only at night, which makes me wonder it was related to the drop in voltage in the cold (old house with high stud, and it can get cold at night). But would that make the alarm emit a warning chirp or actually set it off proper? In our case it's the full-on alarm that goes!

 

As these cheaper Family Shield and Warrior alarms prove, one doesn't have to pay $50 for each alarm to avoid annual battery changes, as both of these are "10 year" units; it's just that both seem like they're prone to false alarms (so to speak!), hence my question as to whether the Cavius alarms are at all prone to the same problem. Still no idea on this yet!

 

I think I'll get Bunnings to do the beat by 15% thing on a couple of Cavius alarms, as $42.50 an alarm sounds ok. But still not sure regarding the value/importance of having the "thermal" model in the kitchen/dining, so would love some advice on this too...


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  Reply # 1592538 14-Jul-2016 14:22
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Never had a false alarm on cavius but plenty on warrior

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  Reply # 1592546 14-Jul-2016 14:30
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RunningMan: Never had a false alarm on cavius but plenty on warrior

 

Good to have this confirmed, thanks.

 

Off to Bunnings this arvo it is, then...


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  Reply # 1592583 14-Jul-2016 14:46
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There are some typical false alarm sources for smoke detectors.

 

For ionisation smoke alarms: Anything, really. They are good at detecting open flame fires, but useless for smoldering fires, and they will go off for most anything: Cooking, high wind/draft, moisture etc.

 

For photoelectric alarms: These are the ones I have always recommended. They warn you for both types of fires, and they don't have as many false alarms.

 

BUT: The photoelectric alarms work by looking at light reflections in the detector chamber. This is a good way of discovering smoke, but it can also see reflections from moisture that gets into the chamber. Its especially tricky to have photoelectric smoke detectors in rooms where the temperature fluctuates and you get condensation of the moisture in the air. This typically happens when the temperature has been above +15 and dips below +15 Celcius.

 

When I was in the business of selling smoke detectors in Norway, we had high season of "problems" with smoke alarms in the spring and autumn - most if not all because of these types of conditions.

 

Another problem is detectors that are open enough that small insects can get into them. The more expensive detectors typically have a mesh protecting the detector chamber against these types of problems.

 

Theres slowly coming in smoke detectors with more smarts that can take temperature into consideration. (A feature that is more or less standard in professional systems already). They are a LOT less susceptible to false alarms

 

The sad fact is that a lot of smoke alarms on the market are really cheap chinese junk, and the parts needed for smart smoke alarms (or even the protective mesh) makes them niche products - because most people only look at the price.

 

The cheap as chinese smoke detectors are sometimes calibrated by hand (so you will have huge variations on how sensitive they are). The calibration is supposed to be done by machine to a set tolerance, but that is not done everywhere. In some cases I know of smoke alarms that have been delivered from the factories without working alarms!





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  Reply # 1592585 14-Jul-2016 14:49
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Very interesting post, thanks.

 

Are there any particular models/brands available in NZ that you'd recommend as good quality/value?


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  Reply # 1592605 14-Jul-2016 15:09
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The smoke detector I would recommend that you can get here in New Zealand is from Irish Ei Electronics. They are sold in New Zealand by Brooks. I would generally recommend interconnected alarms, because you might not hear a smoke detector going off in the opposite side of your house when you are sleeping.

 

http://www.brooks.co.nz/

 

Something like this is what I would look at getting:

 

http://www.brooks.co.nz/index.php/products/smoke-heat-co-alarms/brooks-multi-sensor-230vac-with-rechargeable-lithium-battery-back-up-detail

 

They have both wired 230V, and wireless 9V/10 Year battery versions (and you can also find stand alone versions). These are expensive compared to the cheap chinese, but if you calculate the cost per year by dividing the cost of the detector by 10 (the recommended lifespan of a smoke alarm), then its really not a high price to pay, in my opinion.

 

 





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  Reply # 1592664 14-Jul-2016 16:41
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FWIW, I replaced one of my "regular" smoke alarms with a Cavius unit, being attracted by the 10yr battery life claimed. (and also the aesthetics)

 

It failed after 18months.

 

I will stick with 9V battery operated ones from now on.


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  Reply # 1592680 14-Jul-2016 17:42
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jonathan18:

 

 

 

I was tempted by the aesthetics of the Cavius alarms, but the price is on the steep side. I see that Mitre 10 sells them for $49.99, and Bunnings for $53 - so wouldn't that mean with a price match guarantee Bunnings would need to sell them at $42.50? That doesn't seem quite so bad.

 

 

 

 

In my area Mitre 10 sells them for$53.30, and Bunning $53, where bunnings often  beat them by a few cents, so I always get mitre 10 to do the price beat.  They often say it is only a few cents difference, but that is all it takes.


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  Reply # 1592719 14-Jul-2016 19:25
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jarledb:

 

For ionisation smoke alarms: Anything, really. They are good at detecting open flame fires, but useless for smoldering fires, and they will go off for most anything: Cooking, high wind/draft, moisture etc.

 

For photoelectric alarms: These are the ones I have always recommended. They warn you for both types of fires, and they don't have as many false alarms.

 

BUT: The photoelectric alarms work by looking at light reflections in the detector chamber. This is a good way of discovering smoke, but it can also see reflections from moisture that gets into the chamber. Its especially tricky to have photoelectric smoke detectors in rooms where the temperature fluctuates and you get condensation of the moisture in the air. This typically happens when the temperature has been above +15 and dips below +15 Celcius.

 

I would think that most people in winter like me would heat their living room at night above 15 degrees and then have it drop below 15 degrees while they're asleep. So, for me it sounds like neither ionisation or photoelectric is ideal.


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  Reply # 1592744 14-Jul-2016 19:40
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jonathan18:

Can anyone with the Cavius alarms fitted in their house report on how common (if at all) false alarms are with these units?


And is it worth spending more to get the thermal alarm to replace the one in the dining/kitchen? Generally, apart from the likelihood of false alarms due to cooking etc, are the problems with installing standard photoelectric and/or ionising alarms in such spaces real enough to not make it worth having such an alarm in these spaces?


The Warrior units I've replaced my two "go off in the middle of the cold night" Family Shield alarms with clearly suffer from the same problem, as highlighted above in references to the Consumer members' comments. Excellent - paid a few more dollars to get units that are probably no better. I'm thinking of taking them back for a refund and spending a few more $$$ to get the Cavius. Of course this'll leave a hole exposed on the ceiling, given the units are so much smaller!


I have had mine in for nearly a year and have had zero false alarms. I intentionally put the heat detector in the kitchen to avoid them and in that area though. I have one in the lounge which is very close to the fire and not far from the kitchen and haven't had any issues. I usually test them every 6 months or so. Wear earmuffs when you do though, they are much louder than my old 9v battery ones imo.

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  Reply # 1594445 18-Jul-2016 12:36
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mattwnz:

 

jonathan18:

 

 

 

I was tempted by the aesthetics of the Cavius alarms, but the price is on the steep side. I see that Mitre 10 sells them for $49.99, and Bunnings for $53 - so wouldn't that mean with a price match guarantee Bunnings would need to sell them at $42.50? That doesn't seem quite so bad.

 

 

 

 

In my area Mitre 10 sells them for$53.30, and Bunning $53, where bunnings often  beat them by a few cents, so I always get mitre 10 to do the price beat.  They often say it is only a few cents difference, but that is all it takes.

 

 

Ended up getting the Cavius for $41.56 each, as the local Mitre 10 had them cheaper than the website price. No problems with Bunnings doing their 15% thing, hence the good end price. Pleased with them, especially the testing where pushing the button makes them beep only once, compared to our others which go on and on! Also, a louder alarm which is useful. 


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