The Simplex 4098-9750 is an in-duct smoke detector housing designed to mount on HVAC ductwork and accept TrueAlarm addressable sensor heads for duct smoke detection. The housing incorporates integral sampling tubes that draw conditioned air from the duct across the sensor head, providing reliable detection per NFPA 72 and NFPA 90A duct detector requirements.
The 4098-9750 does not include an onboard relay, making it the appropriate choice when HVAC shutdown is controlled centrally at the panel rather than locally at the detector. For installations requiring a local dry contact relay output, see the relay-equipped 4098-9751.
- Relay output: None (relay-free version)
- Sampling: Integral inlet and exhaust sampling tubes
- Sensor head: Accepts standard TrueAlarm addressable heads
- Loop interface: IDNet / MAPNET II addressable
- Application: Duct smoke detection per NFPA 72 / NFPA 90A
The 4098-9750 is the standard relay-free in-duct housing for Simplex TrueAlarm systems, offering a compact, cost-effective solution for duct smoke detection where local relay action is not required.
For more information, contact the Life Safety Consultants team at (888) 557-0558, or email us at: sales@lifesafetycom.com
Additional information
| Weight | 4 lbs |
|---|---|
| Dimensions | 13 × 11 × 7 in |
| Manufacturers | Simplex |
| Compatible Panels | 4100ES,4020,4010,4008 |
| Compatible Bases | Standard TrueAlarm addressable sensor heads |
| Cross Reference | 4098-9750 |
| Relay | None (relay-free), Sampling: Integral sampling tubes, Head: TrueAlarm addressable, Loop: IDNet/MAPNET II, Application: Duct smoke detection NFPA 72 NFPA 90A |








