How to Choose a Smoke Alarm
Your application or local codes will drive what type of alarms to choose. Whether you’re replacing existing alarms or adding in new, follow these simple steps:
Step #1: Determine Primary ApplicationBattery Operated
- Existing Multi-family/single family (no code for wired-in alarms)
- Replacement of existing battery operated.
- Interconnected alarms not required
Wired-in
- Replacement of existing wired-in
- New construction or remodel (code driven)
- Need to have interconnected alarms either by choice or required by code.
Wireless
- Existing Multi-family/single family (no code for wired-in alarms). Exception: Wireless alarms with both wireless and wired-in features.
- Need interconnected alarms but can’t easily pull wires through existing walls or ceilings.
- Use to bridge between floors
- Use to bridge between old and new construction
- Use to bridge between wired-in and battery operated
- Generally more expensive per alarm but savings are realized through retrofitting costs savings in time, materials and labor.
Step #2: Determine Battery Type
Battery Operated
- Carbon Zinc (standard life) lasts at least 1 year
- Alkaline (extended life) lasts about 2 years
- Lithium (long life) lasts 6-10 years
- Sealed Lithium (true 10 year) lasts at least 10 years
Wired-in
- AC only: Where codes allow such as some motel/hotel applications. Will not operate without AC power.
- AC with battery backup: Required by most codes today. Provides alarm function when power is out.
Wireless
Choose either:
- Battery operated
- Wired-in with battery backup (bridge unit)
Step #3: Determine Sensor TypeBattery Operated
- Ionization: Widely used sensor for many applications, detects small particles produced by flaming fires.
- Photoelectric: detects large particles produced by smoldering fires. Better for nuisance control around kitchens and baths. Required by code in some areas of country like Massachusetts.
Wired-in
- Photoelectric or Ionization (see above)
Wireless
- Photoelectric or Ionization (see above)
