On Monday, March 27, 2017 at 9:38:24 AM UTC-4, wrote:
On Mon, 27 Mar 2017 05:08:44 -0700 (PDT), TimR
wrote:

On Sunday, March 26, 2017 at 11:44:49 AM UTC-4, trader_4 wrote:
On Sunday, March 26, 2017 at 11:04:28 AM UTC-4, wrote:
On Sun, 26 Mar 2017 07:40:48 -0700 (PDT), trader_4
wrote:

2005 when AFCI was only required in BEDROOMS.

There was a requirement for smokes in every "sleeping space"

But depending on where he's located, there may not have
been a requirement that the SMOKE DETECTOR also be in the
bedroom. If the smoke detector was in the hallway outside
the bedroom, which was and still is permitted in many
locations, then AFCI was not required in 2005. And if
it was not required in 2005, then there is no need to
update it now. Do you agree?

On the other hand, if they're all interconnected and on the same breaker, and even one is in a bedroom, then the AFCI is probably required.

I'm not sure that's a good idea, really. If you have an arc somewhere and it trips the breaker, hope it kills the circuit before starting a fire. And there's no other source of ignition (smoking, unattended cooking, etc.) that burns the house down while the smoke detectors are inactive.

That is why they require battery backup.

I think you'll find whether a hardwired smoke detector needs to have
battery backup or not varies from state to state. IMO, it's overkill
and a nuisance. A friend here has a new home and it has about
10 of them that start beeping for a new battery within a year.
Why that is, IDK. You would think the battery is only there for
backup and hence would last close to the shelf life, but they don't.

Every fire death I can recall in the news, it was not the result of AC
power being lost to alarms that were working. The typical scenario is
no smoke alarms, smoke alarms removed, smoke alarm broken, smoke alarm
with a dead battery, etc. My house has AC only alarms and that's what
I prefer.