Smoke Detectors Part II: Sounders

[rocco]

Rocco is correct and although aware, probably forgot to mention that the 120V detectors must also have a backup battery (usually 9V).

Actually, Peter, this is where I found the code to be 1) inflexible, 2) arbitrary, and 3) silly (alright, maybe downright stupid).

The borough did not require battery backup. They approved this smoke-detector.

I feel that a low-voltage smoke-detector, powered from an alarm panel that has a battery for backup, would be safer. Yet the code did not allow it. The code required 120VAC smoke-detectors, but did not require battery backup for them.

I guess I am just reiterating upstatemike's comment about rules being weird.

 

[jlehnert]

Where do you guys live that has all these weird rules

I'd have to say "What weird place do you live were they DON'T have these rules?" Most jurisdictions in the US have adopted some version of the NEC/NFPA rules, as insurance companies tend to raise rates in locations that don't. Enforcement is a different subject. Generally, the greater the population density, the better the enforcement. It reminds me of a former neighbor who moved out to someplace west of the end of the world (AKA Arkansas). He drove into the county seat to inquire about a building permit, septic field permit, etc for a new house. The guy behind the counter said "Whyinhell would you need permits to build a house? It's your land isn't it?"

To expand slightly on something Peter said.

The "linked sounder" and "mains power with battery backup" requirements are for new construction and major remodelling. They do not apply to existing houses (but are highly recommended).

If linked integral sounders are required by code, why do they make smoke detectors that do not have them?

Depends on were you are seeing them. Remember that Home Depot/Lowes and their ilk cater to the remodelling crowd and thus the new construction/major remodel rule would not apply. If you are adding or replacing a smoke detector in an existing house, then you really can't link the units (unless they are already linked). I did notice recently though, that HD had some replacement smoke detectors that were linked by rf, so an older house could be easily updated to the linked sounder spec.

As for the "weird" rules, the first time I heard about them I also said "What idiot came up with this $#%^@$ rule?" However, they actually make sense after you sit down and work them through. Mains power --> becuase people habitually forget to change the batteries. Linked sounders --> so you aren't sleeping at one end of the house while the other end is shooting flames 30 ft into the air. And etc.

 

[jlehnert]

Actually, Peter, this is where I found the code to be 1) inflexible, 2) arbitrary, and 3) silly (alright, maybe downright stupid).

Was this the actual written code (unlikely but possible) or the code as interpreted by an inspector (more likely, but still legal as he is the AHJ)?

This is one problem with the "national" code. In reality it has no legal standing until each jurisdiction enacts a law to make it legal. The jurisdiction can also enact only parts of the code, or use an older version (NFPA 72 is updated every three years). Finally, after it gets bent folded and mutilated by the politicians, the local AHJ (AKA the palooka inspector hired because his brother is the mayor) gets to add HIS (or her) interpretation of it.

And for "inflexible, arbitrary, and stupid"....yep, I agree with you.

 

[upstatemike]

Generally, the greater the population density, the better the enforcement.

Greater population density is never a good thing... Usually means a lot of uptight people from downstate are making life more complicated than it needs to be!

This probably explains why I haven't heard much on this locally.