Smoke Alarms

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Oddlot
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Smoke Alarms

Post by Oddlot » Wed Jan 23, 2013 12:24 pm

It's time to replace a hardwired smoke alarm in the upstairs hallway. While this unit meets the state code, I plan to also add a unit on the first floor as well as one in the basement.

Apparently there are only two smoke alarm manufacturers (Kidde and First Alarm /BKR), yet there are many models and feature choices. I have looked at Amazon and Consumer Reports, and numerous comments on their sites reflect widespread disappointment in the poor quality and/or the high frequency of false alarms. Thus the purchase decision seems to merit more consideration than buying the cheapest thing I can find.

I am leaning towards hardwired w/battery backup, dual sensor (detect smoke & flame), & interconnected (all detectors sound at once). There are some that also include CO detection.

Any thoughts about what type and features? Model recommendations? While I can replace the existing hardwired unit (assuming wiring/mounting compatibility of course), is it beyond the skills of the typical DIYer to install a new hardwired unit?

Thanks for the input.

Oddlot

lindisfarne
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Re: Smoke Alarms

Post by lindisfarne » Wed Jan 23, 2013 12:38 pm

Oddbot,
I personally have decided against the smoke alarm/CO detector combination because CO detectors need to be replaced more frequently than smoke alarms (every 5-7 years). For hard-wired systems, you need to get a smoke alarm that is compatible with the existing system - or else you can get false alarms. You also need to make sure the smoke alarms are placed correctly. The one near my kitchen false alarms if I'm boiling something on the stove - seems to be steam that does it. I, too, saw the reviews on Amazon & it's hard to say whether some of them are caused by not replacing with an alarm compatible with the others in the system, steam (too close to the bathroom?), or problems with Kidde. I replaced one a year ago (Kidde PI2010) and have had no problems with it. I could be complaining in 5 years ago problems with it - who knows? You can find the package inserts online with a little google work (Kidde has some). Read it carefully for compatibility - it does say which Kidde (& Firex) models are compatible.

For CO alarms, I use the ones that are separate from fire alarms. Some alarm at a predetermined level; others will give you more info & a digital display of the level (there are different alarm parameters that cause an alarm: lower but longer-lasting CO will cause an alarm eventually). I saw there are some now with 7 year warranties, but that's the longest I've seen; many are 5 year (& it can differ across models of same manufacturer. I'm not sure what is different, but UL standards are strict.

I also thought about skipping the hard-wired system & just going with the battery backup option that you don't hard-wire - those certainly are a lot cheaper. My house is small enough I could hear them anywhere. I'd do that if I had a lot of unexplained false alarms - but so far, no problem with the 2 I've replaced. I have 5 of them, 4 on the second floor, all within about 10 feet of each other (hallway + 3 BR), so I'm replacing them over time so that I always have a newer one in the system.

Note:Amazon's prices on the Kidde 2010 have fluctuated between about $22 (bought 1 a couple of weeks ago) to about $33 in the last year (the one I bought a year ago was about $28.

Contact your hazardous waste people - smoke alarms may need to be taken to a haz waste site given the electronics & radioactive americinium that's part of the detector.

Rupert
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Re: Smoke Alarms

Post by Rupert » Wed Jan 23, 2013 1:00 pm

For what it's worth . . . I recently updated some of my heat & smoke detectors. ADT installed them because they're plugged into my security system. The ADT installation guy said the combo smoke/heat/CO sensors are a bad idea. He said the CO sensors need to be near probable sources of carbon monoxide, not on the ceiling or high on the walls with your smoke & heat detectors. I have them near my gas furnace unit and near HVAC vents in my bedrooms. If you have a gas stove or water heater, you would also need them near there. ADT guy also recommended just heat detectors in/near kitchen and laundry room and just smoke detectors for hallways and bedrooms.

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southerndoc
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Re: Smoke Alarms

Post by southerndoc » Wed Jan 23, 2013 1:56 pm

If someone were to replace hardwired alarms, who would he or she contact to do this if instead of doing it yourself?

We purchased a house built in 2007 that set vacant until we purchased it in 2010 (builder went bankrupt, was tied up in courts). The alarms have changed colors slightly, which I've been told is an indication they need to be changed. We have 8 alarms in our house (not counting the ones installed by ADT).

lindisfarne
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Re: Smoke Alarms

Post by lindisfarne » Wed Jan 23, 2013 2:25 pm

southerndoc wrote:If someone were to replace hardwired alarms, who would he or she contact to do this if instead of doing it yourself?

We purchased a house built in 2007 that set vacant until we purchased it in 2010 (builder went bankrupt, was tied up in courts). The alarms have changed colors slightly, which I've been told is an indication they need to be changed. We have 8 alarms in our house (not counting the ones installed by ADT).
The actual replacing of the alarms is pretty easy (at least mine are -twist, then squeeze the connector that hooks the system up to the alarm). If you're worried about compatibility: just buy the same as what you have. If for some reason you can't do it yourself, I'd assume you could get almost anyone to do it for you (housekeeper? someone with a ladder? handiperson? I'd just want to supervise unless it's someone you trust.).

Rupert
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Re: Smoke Alarms

Post by Rupert » Wed Jan 23, 2013 2:44 pm

I would hire an electrician to do it if I couldn't do it myself.

wingnutty
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Re: Smoke Alarms

Post by wingnutty » Wed Jan 23, 2013 10:10 pm

Here's what I've decided to do in our situation after a lot of thinking and comparing different options. Our alarms are all old and need replacement.

We have 2 hard-wired CO detectors and 8 hard-wired ionization alarms. I'd like to add a few photoelectric alarms as well, but don't want the combo ionization/photoelectrics because they are a bit more expensive than the ionizations and I'd need 8 of them. So, I'm going to get 2 combo CO/photoelectrics to replace the CO alarms and then just go with 8 ionization alarms to replace the existing ionization alarms. I know CO alarms only last 5-7 years, but I like being able to have all 3 bases covered (ionization, photoelectric and CO) at the the least price.

So for ~$170, I can get all of the alarms and cover all 3 bases pretty well.

I'll replace them myself since they are very easy, but if a person didn't want to do it themselves, I am sure any electrician could do it pretty quickly.

lwfitzge
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Re: Smoke Alarms

Post by lwfitzge » Wed Jan 23, 2013 10:55 pm

lindisfarne wrote:
southerndoc wrote:If someone were to replace hardwired alarms, who would he or she contact to do this if instead of doing it yourself?

We purchased a house built in 2007 that set vacant until we purchased it in 2010 (builder went bankrupt, was tied up in courts). The alarms have changed colors slightly, which I've been told is an indication they need to be changed. We have 8 alarms in our house (not counting the ones installed by ADT).
The actual replacing of the alarms is pretty easy (at least mine are -twist, then squeeze the connector that hooks the system up to the alarm). If you're worried about compatibility: just buy the same as what you have. If for some reason you can't do it yourself, I'd assume you could get almost anyone to do it for you (housekeeper? someone with a ladder? handiperson? I'd just want to supervise unless it's someone you trust.).
It was very easy (just need a ladder and pop in) and relatively cheap to replace all (<$20 each, non combo). If hard wired to a service, compatibility is a consideration. We were suffering from false alarms with the ionization type and replaced all with the photoelectric types and since have not had a single false alarm.

dewey
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Re: Smoke Alarms

Post by dewey » Thu Jan 24, 2013 1:04 am

I may be mistaken--but my assumption is the hard wired/universally connected systems make most sense for multi-level houses so that you are alerted to a fire no matter where it originates (e.g. you sleep on the second floor but a fire erupts in the basement). A one level house is different in that, at least for our small house, a smoke alarm sounding in any part of the house will alert us in any other part of the house even while sleeping. The problem with modern homes is codes requiring the linked systems that others have noted go off if boiling water or if a flatulent mother-in-law is visiting. And--when one blasts they all blast (speaking of the smoke detectors here). Crazy. If you substitute photoelectric sensor devices, they are more forgiving of boiling water, etc. etc. according to my friend the fire chief. My insurance company assures me the alarms are for resident safety--not insurance purposes.
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Valuethinker
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Re: Smoke Alarms

Post by Valuethinker » Thu Jan 24, 2013 2:55 am

dewey wrote:I may be mistaken--but my assumption is the hard wired/universally connected systems make most sense for multi-level houses so that you are alerted to a fire no matter where it originates (e.g. you sleep on the second floor but a fire erupts in the basement). A one level house is different in that, at least for our small house, a smoke alarm sounding in any part of the house will alert us in any other part of the house even while sleeping. The problem with modern homes is codes requiring the linked systems that others have noted go off if boiling water or if a flatulent mother-in-law is visiting. And--when one blasts they all blast (speaking of the smoke detectors here). Crazy. If you substitute photoelectric sensor devices, they are more forgiving of boiling water, etc. etc. according to my friend the fire chief. My insurance company assures me the alarms are for resident safety--not insurance purposes.
Ionization alarms are sensitive to fire, photo electric to smoke. Since what kills you is usually a smokey fire, PO are somewhat safer in that regard. But for safety you need both.

I think an ionization alarm is therefore sensitive to cooking and ?also? to showers?

The real reason for hardwired systems is that battery only tend to get deactivated over time (plus the problem of hearing them over the whole house, as you say). The battery runs out, the warning sounds, it's annoying, someone pulls the battery out. Something like over 50% of battery detectors, I think I read, are actually not powered up. Human nature. Thus in a rental situation (or with older people) I'd definitely go with hard wired (they are Building Regs here when you renovate).

If you do go the battery route, go for lithium batteries. The extra expense is more than deferred by the reduced annoyance of having 3-4x the battery life-- the low battery alarm (ours is almost impossible to echo locate, we wind up checking *all* the alarms) goes off in the middle of the night etc. etc.
Last edited by Valuethinker on Thu Jan 24, 2013 2:58 am, edited 1 time in total.

Valuethinker
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Re: Smoke Alarms

Post by Valuethinker » Thu Jan 24, 2013 2:57 am

Rupert wrote:For what it's worth . . . I recently updated some of my heat & smoke detectors. ADT installed them because they're plugged into my security system. The ADT installation guy said the combo smoke/heat/CO sensors are a bad idea. He said the CO sensors need to be near probable sources of carbon monoxide, not on the ceiling or high on the walls with your smoke & heat detectors. I have them near my gas furnace unit and near HVAC vents in my bedrooms. If you have a gas stove or water heater, you would also need them near there. ADT guy also recommended just heat detectors in/near kitchen and laundry room and just smoke detectors for hallways and bedrooms.
+1 CO sensors need to be separate. Near the furnace.

Apparently the shower room is a risk. I am not sure I understand how this works, but the engineer said that the moisture when you are having a shower displaces oxygen and so it's a particularly risky place for CO buildup. The other place is of course the kitchen if you cook with gas.

MrMatt2532
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Re: Smoke Alarms

Post by MrMatt2532 » Thu Jan 24, 2013 7:14 am

Valuethinker wrote:
Rupert wrote:For what it's worth . . . I recently updated some of my heat & smoke detectors. ADT installed them because they're plugged into my security system. The ADT installation guy said the combo smoke/heat/CO sensors are a bad idea. He said the CO sensors need to be near probable sources of carbon monoxide, not on the ceiling or high on the walls with your smoke & heat detectors. I have them near my gas furnace unit and near HVAC vents in my bedrooms. If you have a gas stove or water heater, you would also need them near there. ADT guy also recommended just heat detectors in/near kitchen and laundry room and just smoke detectors for hallways and bedrooms.
+1 CO sensors need to be separate. Near the furnace.

Apparently the shower room is a risk. I am not sure I understand how this works, but the engineer said that the moisture when you are having a shower displaces oxygen and so it's a particularly risky place for CO buildup. The other place is of course the kitchen if you cook with gas.
As an engineer I'm going to call BS here regarding the shower CO situation. The mole fraction change of CO due to the he presence of water vapor is negligible. CO is an issue where we have incomplete combustion.

The presence of the water vapor can cause the sensor to possibly malfunction, so you probably don't want the sensor too close to the shower.

Valuethinker
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Re: Smoke Alarms

Post by Valuethinker » Thu Jan 24, 2013 8:40 am

MrMatt2532 wrote:
Valuethinker wrote:
Rupert wrote:For what it's worth . . . I recently updated some of my heat & smoke detectors. ADT installed them because they're plugged into my security system. The ADT installation guy said the combo smoke/heat/CO sensors are a bad idea. He said the CO sensors need to be near probable sources of carbon monoxide, not on the ceiling or high on the walls with your smoke & heat detectors. I have them near my gas furnace unit and near HVAC vents in my bedrooms. If you have a gas stove or water heater, you would also need them near there. ADT guy also recommended just heat detectors in/near kitchen and laundry room and just smoke detectors for hallways and bedrooms.
+1 CO sensors need to be separate. Near the furnace.

Apparently the shower room is a risk. I am not sure I understand how this works, but the engineer said that the moisture when you are having a shower displaces oxygen and so it's a particularly risky place for CO buildup. The other place is of course the kitchen if you cook with gas.
As an engineer I'm going to call BS here regarding the shower CO situation. The mole fraction change of CO due to the he presence of water vapor is negligible. CO is an issue where we have incomplete combustion.

The presence of the water vapor can cause the sensor to possibly malfunction, so you probably don't want the sensor too close to the shower.
Ok the guy was dead straight but he could have been wrong. At that time my boiler (ie hot water and rad heat furnace) was in the back of the bathroom, so that may have been what he meant. I was surprised when he said it.

A note on language which still confuses me. In North America my father was 'a Professional Engineer' and that meant he had a university degree and a certain number of years practice in the field.

In the UK 'engineer' is a much broader term, can simply mean someone who did an apprenticeship and qualified which is what your average plumber does to work on gas boilers (used to be called something called 'CORGI registered').

So I did not mean to imply the guy was a P.Eng. in a North American sense. No iron ring ;-).

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Kenkat
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Re: Smoke Alarms

Post by Kenkat » Thu Jan 24, 2013 11:22 am

I replaced all of my hard wired smoke alarms fairly recently. The old units were around 12 years old. I replaced them with KIdde PI2010. I liked the dual sensors and this unit seemed to have the fewest falsing or malfunction complaints. So far so good.

In my case, the plug-in connectors from the old units fit the new units perfectly, so it was an easy swap. I did have to install new brackets to hold the new detectors but I was able to use the existing drill holes. Quick and easy.

To install a new hard wired unit, you would have to run wires thru walls and/or attic. Maybe something best left to an electrician.

I do believe they now have wireless detectors that can be interconnected without running new wires. That might be a good option to consider.

killjoy2012
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Re: Smoke Alarms

Post by killjoy2012 » Thu Jan 24, 2013 12:21 pm

I would strongly suggest you research, or ask the professionals, what the local building & electrical codes are in your specific area. You have the NEC (2002, 2008 or 2011 versions... and you need to know which version your city follows) and Residential Building Codes, but then it's also common for local cities to amend certain things. There's no way to know all of the requirements w/o taking your locality into account.

Just some tips/thoughts to make sure you've accounted for everything if you DIY:
- Every floor of the house needs a smoke detector. Every bedroom. Every hallway/common area directly outside of a bedroom area.
- Many areas require a/the CO detector to be in the hallway directly adjacent of the bedroom area.
- Don't place the CO detector in close proximity of the furnace / water heater, unless you really like the alarm going off often for no purpose. These devices do put off CO, and if you want/need one in the basement, that's fine... I wouldn't put in very close proximity unless you like false positives occurring often.
- All of the smokes/COs need to be interconnected so that if one goes off, all go off. This is generally done by running 14-3 between all devices on the same 15A branch circuit. The circuit does not need to be dedicated to the smoke detectors, but all detectors must be on the same branch circuit.
- That circuit must be AFCI protected since the smokes will be in bedrooms, per code.
- Battery back up is not an option - required.

Oddlot
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Re: Smoke Alarms

Post by Oddlot » Fri Jan 25, 2013 12:37 pm

killjoy2012 wrote:I would strongly suggest you research, or ask the professionals, what the local building & electrical codes are in your specific area.
KJ: Good suggestion. I checked and my village "requires a smoke detector on each level of a residence and one in each bedroom. CO detectors are required within 15 ft of any sleeping room."

I have to admit this has been a wake-up call (pun intended). Also, other input on the thread greatly appreciated.

Oddlot

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stickman731
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Re: Smoke Alarms

Post by stickman731 » Sat Jan 26, 2013 6:41 am

Two important things to remember about smoke / CO alarms besides replacing the batteries twice a year.

1. The sensors lose sensitivity over time and need to be replace every couple of years (regardless if hardwire or not).
2. Make sure you can register the product on the manufacturer's website to receive recall notices. I do not believe you can register the Kidde products on-line or at all, just look on their website and you will see product recalls. I purchased two Kidde alarms from Lowe's only to find out later about the registration issue. I returned them and got FirstAlert products from Home Depot.

I truly feel that any safety or household product should have mandatory product registration in order to alert consumers to product recalls that could jeopardize them and their family. The burden should not be placed on the consumer to monitor all product recalls. Manufacturers should have an obligation to alert registered users.

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