值得一看的紐西蘭消費者測試報告-煙霧警報器及電池

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紐西蘭消費者機構做的關於煙霧偵測器及電池的測試比對，鏈接如下

https://www.consumer.org.nz/prod ... batteries/overview/

PRODUCT OVERVIEW

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Smoke alarms and batteries

Smoke is toxic –and breathing it can kill. So you need an alarm that gives you early warningand more time to escape. We tested 9 photoelectric, 3 dual-sensor and 8ionisation smoke alarms. We also tested 19 9-volt batteries, specifically fortheir performance in smoke alarms.

About our tests

We tested 20 smoke alarms and 19 9-voltbatteries.

Smoke alarms test

Our test was conducted in the firelaboratory of the Building Research Association (BRANZ). We purchased 3examples of each model. Our results are the average of the performances of the3 examples.

The alarms were fixed to a ceiling panel ina mocked-up hallway adjacent to the door opening of a fireproof room (which wasabout the size of a single-car garage).

•  The flaming fire test: 3 pieces of 40mm-square 300mm-long sticks were set alight using a smallquantity of methylated spirits. The resulting smoke built up in the room andflowed into the mock hallway.

•  The smouldering fire test: A 60W electric soldering iron was pre-heated and laid horizontally on toa 1.2 kg piece of 70mm-thick polyurethane upholstery foam. An electric fan wasused to evenly distribute the resulting smoke out into the mock hallway.

In both tests,the smoke density was measured at the location of the alarms using a laserlight-source and detector.

Smoke alarm batteries test

This test was specifically designed toobtain information about the batteries’ performance when powering a smokealarm. The results aren’t an indication of their performance in otherdevices.

Smoke-alarm batteries have a challengingtask to perform. They sit in the alarm over a long time – and can be called onto power the siren when they’re likely to be in a semi-discharged state. What’smore, it could be a cold night when they’re needed (batteries don’t function aswell in the cold as they do when warm).

There were 4 steps in our testing:

•  To tailor our battery tests to smoke alarms, we took 3 different alarmsand measured their electrical characteristics both on standby and when thealarms were sounding.

•  We measured the capacity (stored electrical energy) of each battery bymonitoring the time it took when we deliberately discharged each from itsinitial 9 volts to 5.

•  We took another set of our test batteries and half-discharged them usingthe data from step 2.

Thesehalf-discharged batteries were refrigerated to 6°C and then set up to supplythe electric current equivalent to a sounding smoke alarm. We measured how wellthey performed this task.

Test results

Test results and recommendations from ourtests of smoke alarms and batteries. You can also compare details in our interactive test results.

Smoke alarms

Guide to the table

Price is what we paid in December 2013.

Overall score

•  Flaming fire (50%)

•  Smouldering fire (50%)

Smoke alarm batteries

Guide to the table
This test was specifically designed toobtain information about the batteries’ performance when powering a smokealarm. The results aren’t an indication of their performance in otherdevices.

Price is per battery and is from a survey inMarch 2014.

Overall score

•  Capacity (50%)

•  Cold performance (50%)

•      

•      Which type of smoke alarm?

•     It could be a deadly mistake thinking you’re protected by the most commontype of smoke alarm.

•      Smoke is not just smoke. Smoke from flaming wood or cooking-oil fires isdifferent from that produced by the cooler smouldering of upholstery foam,bedding or the plastic components in electrical equipment.

•      Ionisation alarmssense the volatile combustion products from hot flaming fires. But they don’tdo as good a job sensing the smoke from smouldering fires because fewercombustion products are present.

•      Photoelectric alarms shine a light beam across a chamber and detect if the air in thechamber becomes partially obscured. So they can detect smoke from both types offires.

•    Our test findings

•      In 2006 and 2010 we tested how well photoelectric and ionisation alarmsreacted to smoke from a flaming wood fire or a smouldering fire. The two alarmsoperate differently in detecting the presence of smoke (see above). We foundthat photoelectric smoke alarms gave you significantly more protection than themore common ionisation models – particularly for smoke from non-flamingsmouldering fires.

•      Our new test reinforces our earlier findings. Thistime we tested 9 photoelectric, 3 dual-sensor and 8 ionisation models – 20 intotal. We tested them against a flaming wood fire and smouldering upholsteryfoam, both with steadily increasing smoke levels.

•      The dual-sensor models and all the photoelectricmodels gave the best protection from both types of fire.

•      The ionisation models were slightly better overall at detectingflaming fires – but they were hopeless for smouldering fires. None of themsounded at all during our smouldering fire test-runs. That failing ispotentially fatal.

•      Using dual-sensor alarms is the deluxe solution. But they’re not that muchof an advantage over our recommended photoelectric models.

•      The key to your protection is to have several good photoelectric alarms inworking order. See 'Code requirements' below for advice on where to place thealarms.

•    Which type have you got?

•      Ionisation models require a tiny amount of radioactive material to makethem work. So all of them will have the radiation symbol somewhere on theplastic body.

•      Tip: If your househas ionisation alarms, supplement (or replace) them with our recommendedphotoelectric models.

Battery types

9-volt smoke alarm batteries come in 3types, ranked by increasing energy storage and price:

•  the original carbon-zinc (often labelled “heavy duty”)

•  alkaline (which hold more energy and so last longer)

•  lithium (which hold even more energy and can last in a smoke alarm formany years).

Our testing shows a good alkaline batteryhas about twice the life of a carbon-zinc battery – and a good lithium batteryhas 3 times the carbon-zinc’s life.

The “coldperformance” score in our test looks at how well a cold and half-dischargedbattery could power a sounding smoke alarm. The good news is that all typesof smoke-alarm batteries were capable of sounding an alarm when cold andhalf-discharged.

Best batteries

If you want the longest life possible, the EclipseLithium has the highest storage capacity. But at $17.90 it’s expensive.

At around two-thirds the capacity of theEclipse, the Arlec Alkaline Maximum Performance is worth considering –and it’s only $3.98.

And while it hasonly about one-third the storage capacity of the Eclipse, if you change yoursmoke-alarm batteries every year, we think the $1.99 Warrior Super HeavyDuty is good value for money.

Burnt toast

False alarms can be a problem in kitchensand other places where steam or cooking smoke can get near the smoke alarm.Some manufacturers don’t recommend putting an alarm in these areas. We thinkyou can – so long as you take some precautions. So here’s a few tips:

•  Install photoelectric alarms. They’re less likely to give out a falsealarm when you’re cooking.

•  For the kitchen only, look at installing a less-sensitive model that’s towards the bottom ofthe photoelectric models in our Test results.

•  Use extractor fans or range hoods to remove kitchen fumes and bathroomsteam.

Be careful whereyou install alarms on the ceiling. Place them as far away as possible frombillowing steam or cooking fumes.

Code requirements

Along with a raft of other changes as aresult of the leaky building crisis, the building code was changed in 2003 torequire smoke alarms to be fitted to all residential buildings.

This doesn't mean that a council inspectorwill come knocking on your door to check if you have fitted the alarms. But itdoes mean that a code compliance certificate won't be issued - for any buildingwork that requires a permit - until the alarms are fitted.

The rules

According to rules set down by the BuildingCode, smoke alarms must be "type 1" units. This means they must havea hush button - to allow nuisance alarms to be cleared without removing thebattery - and also a test button.

As well, they must comply with at least oneof the following standards:

•  UL 217

•  CAN/ULC S531

•  AS 3786

•  BS 5446: Part 1

Where to fit alarms

According to the rules, smoke alarms mustbe located in escape routes on all levels within the household unit. On levelscontaining sleeping spaces, they must be installed within the sleeping space,or within 3 metres of every sleeping space door. And they must be audiblethrough closed doors.

Alarms must be installed on or near theceiling, and in accordance with manufacturer's instructions.

You will need several alarms for largehouses or multi-level houses. If you buy the inter-connectable type and wirethem up, all will go off together. Tests have shown an upstairs alarm in thestairwell is likely to respond before one fitted downstairs, even when the fireis downstairs.

The NZ Fire Service also has advice on where toplace alarms.