This is the most plausible explanation... The house is conventional stucco exterior, frame construction, non-Chinese sheetrock, latex paint, some carpeting. It is very energy efficient and tight. 9ft ceilings throughout on one floor (slab, no crawl-space or basement)It is possible that "new house" off-gassing (even after 2 years) is tripping the ionization type smoke detectors. You could switch to the photo-detector type and see if that helps. The gas builds up at the ceiling at night when the air is still.
The first batch were FireX Ionization Smoke Alarms, model i4618A. The second batch are similar, just a different manufacturer. Some of the alarms are a single loud chirp, which do not trigger the other alarms. Others are full-on alarms that last for several minutes (but do eventually time-out) but do trigger all the alarms at once. AFAICR, one of the early units failed in a mode where the only thing that shut-it up was disconnecting it from the AC and removing the 9V battery.What type do you have? Use ionization type near kitchens to reduce the likely hood of false alarms do to burned toast etc. Use the photo-detector type near the bedrooms where smouldering type fires are more likely. Either will work in either situation regardless. It more about reducing false alarms and preventing the homeowner from riping the unit from the ceiling and throwing it out the window.
No kind of power supply problem should ever put a smoke detector into full alarm mode. It could, however, sound a short chirp to signal that the power has glitched, gone off, or come back on.
If you are smoking in our house, you'd better be on fire. (Just ask my wife).Is anyone in your household a smoker? Over time a thin layer of smoke particles can build up on ceilings, and ceiling-level alarms, and perhaps cause drift of some circuit parameter.
LOL. Same in my house.you'd better be on fire
I just noticed something else. The branch circuit that powers the smoke detectors has a 15A Arc-Fault type of circuit breaker (likely because some of the smoke detectors are in bedrooms, and code requires all branch circuit going to bedrooms to be Arc-Fault). The current draw in that branch is likely to be only a couple of mA. Is there something about very-lightly-loaded Arc-Fault C.B.s that could cause the false alarms in the smoke detectors?Still an ongoing problem. ...
I think you'll find that only applies to receptacle circuits..I just noticed something else. The branch circuit that powers the smoke detectors has a 15A Arc-Fault type of circuit breaker (likely because some of the smoke detectors are in bedrooms, and code requires all branch circuit going to bedrooms to be Arc-Fault). The current draw in that branch is likely to be only a couple of mA. Is there something about very-lightly-loaded Arc-Fault C.B.s that could cause the false alarms in the smoke detectors?
Maybe, but the commercial electrician that wired the house ran a unique circuit that goes only to the smoke detectors, and nowhere else. That circuit is protected by an Arc-Fault type of breaker.I think you'll find that only applies to receptacle circuits..
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That's what I would do. And it's always recommended (but not code required) to put your smoke detectors on a dedicated circuit.Maybe, but the commercial electrician that wired the house ran a unique circuit that goes only to the smoke detectors, and nowhere else. That circuit is protected by an Arc-Fault type of breaker.
Are you suggesting that I exchange the Arc-Fault with a standard breaker?
@MikeMLMy house was built in the '70s and it has hardwired 120V smoke detectors as well. I tended to set them off by accident while running my small (4" tall) Tesla coil in the basement. Electro-magnetic interference tends to trigger them. It could be caused by a fan motor or other appliance (furnace ignitor? Air conditioner? Refrigerator cooling system?) turning on or off. Mine were on a separate breaker but I would still set them off with my TC.
In the three years we have been in the house, the highest incidence of alarms seems to be in the summer months (now). We are in the monsoon season, where moisture streams up from the gulf of Mexico, raising the relative humidity to about 35% (from our normal of 5 to 10%), so this is the time when static electricity is the least... Even at its highest, our relative humidity is a fraction of what it would be in Texas or Florida...@MikeML
Do you have staticelectricity issues all year in Arizona or just in winter? Could it be a static issue?