Security & Fire Protection Systems/home smoke alarms


QUESTION: Hello.  I've been all over Amazon, Lowe's, etc. trying to get an acceptable alarm (or two or three). No matter how many stars, there are always a few to claim they are rubbish. Flame vs. smoldering, 10-year battery vs. replaceable or wired---I don't know what to think. The three I have are old but work. I know because I just waved flaming newspaper nearby them. They never give a false alarm. But I live in a split-level house and have a high frequency hearing problem and would not be awakened by any except the one outside my door in the hallway, upstairs. If the other two were good and loud in the audible mid-range, that would be good. Can you recommend something?

ANSWER: Hello Jim, and thanks for your questions.

You're right -- there are a lot of choices out there, and a lot of opinions both pro and con for every one of them.

I'll give you my opinion in general terms, and then add a suggestion.

Photoelectric vs. ionization: the debate about which is best has been going on forever. Based on my experience and several long-term studies, I lean toward photoelectric. But you won't catch me calling ionization detectors junk either.

Hard-wired? Yes. That's both AC power and interconnecting wiring between detectors.

Battery back up? Absolutely. A simple 9-volt battery lasts about a year in most detectors and ensures the alarm will work during a power failure.

Brand preference? No, not really. I trust the work done by Underwriters Laboratories, so any brand that carries the UL label should be fine. Every major brand's products are tested.

In general then, to summarize: AC powered photoelectric detectors with battery backup, interconnected so that when one detects smoke, all of them sound the alarm.

Now, since you said you're hearing impaired, a suggestion. Get at least one detector that's designed for that specific use.

Here's a link to some general information from NFPA:

And here's a link to a specific product that's available from Home Depot (online):

I hope this information helps, and if you have additional questions, just let me know.

Best Regards,


---------- FOLLOW-UP ----------

QUESTION: Thanks for the info.   I have battery-powered independent units.  How do the wired ones work?  That is, how do you wire them in a house? Drill the walls? Plug into outlets? Drape leads all over?  I see the value of connecting at least two of them: the one in the garage to the one upstairs in the hall. Also, I don't remember seeing just a photoelectric unit. I've seen combos. What do you think of those?

Hello again, Jim.

I'm assuming your residence is older construction; for many years California code has required interconnected smoke detectors in new construction. Interconnected smoke detectors are typically powered by 120 volts AC on a single circuit. There's a third wire that's used to interconnect them so that when any one goes off, all of them sound the alarm...So, to come up to that standard, you'd need an electrician to run wires (likely in the attic space)to power and interconnect the detectors.

Since you're using single-station battery operated detectors, you're somewhat limited in your choices. I don't know of any hearing-impaired detectors that are not hard-wired.

But you can certainly replace your detectors with those of like-kind, and even add more inside the sleeping areas instead of just outside them.

To your second question about combination detectors, these fall into two categories; those with smoke and heat detection, and those with smoke and carbon monoxide detection. I know of no models that combine both photoelectric and ionization as the detection method for smoke. In terms of personal preference, I think smoke/heat detectors are fine.

I prefer smoke and carbon monoxide detectors be separate, based solely on the opinion that smoke detectors should be mounted high (where the smoke rises), and carbon monoxide detectors should be mounted low, where CO gas accumulates.

I hope this helps!

Best Regards,


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Dave Neuweiler


The design and application of burglary and fire systems for homes and businesses. Helping alarm owners understand how their system works. Helping to troubleshoot false alarm problems. Questions about monitoring issues.


Over a quarter century in the industry. Experience in installation, service, and monitoring centers. Training manager for a national protective services company; director of education and training for a national trade organization for for alarm dealers.


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