The Dahua DHI‑HY‑SA21A‑W2 Wireless Smoke Alarm is a high‑performance, battery‑powered smoke detection unit designed for residential and light commercial settings. It integrates advanced split‑spectrum photoelectric sensing with low power consumption and wireless connectivity to deliver early smoke detection and fast alerting—without needing mains wiring. Notifications can also be relayed through Dahua’s DMSS app in real time for enhanced safety awareness.
This model is ideal for villas, shops, apartments, and other indoor spaces where minimal wiring and reliable smoke sensing are required.
✅ What’s Included in the Box
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1 × Dahua DHI‑HY‑SA21A‑W2 Wireless Smoke Alarm
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Mounting screws and wall plugs
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User / installation manual
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Battery (CR123A) — typically included (confirm with supplier)
🌟 Main Features
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Split‑spectrum photoelectric sensor technology for improved sensitivity and reduced false alarms
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Test & Silence single button: easily test the alarm or silence nuisance triggers for ~12 minutes
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Loud alarm output: ≥ 85 dB(A) at 3 meters distance
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Low quiescent current consumption for extended battery life
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Wireless communication (433.1 MHz – 434.6 MHz) with two‑way signaling, frequency hopping, and AES128 encryption
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Long communication range—up to 1000 m in open spaces
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Multi‑alarm types: smoke alarm, fault warning, and low battery alert
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Visual & audible signaling: red & green LEDs for status (standby, alarm, fault, battery low)
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CE & TÜV certified, compliant with EN 14604:2005 + AC:2008 standard
📊 Detailed Specifications
| Parameter |
Specification |
| Model / Part Number |
DHI‑HY‑SA21A‑W2 |
| Detection Principle |
Photoelectric (split‑spectrum) |
| Sampling Period |
10 seconds |
| Alarm Types |
Smoke alarm, fault warning, low battery warning |
| Alarm Output / Volume |
85 dB(A) to 90 dB(A) at 3 m |
| Silence Duration |
~ 12 minutes |
| Alarm Response Threshold |
0.2 dB/m – 0.3 dB/m |
| Coverage Area |
20 m² to 40 m² (for ceiling height < 8 m) |
| Battery / Power |
3 V (CR123A lithium, replaceable) |
| Battery Life |
Up to 3 years under normal stand-by conditions |
| Operating Current |
≤ 35 µA (monitoring), ≤ 35 mA (alarm) |
| Operating Temperature |
–10 °C to +55 °C |
| Operating Humidity |
≤ 95 % RH (non‑condensing) |
| Wireless Frequency |
433.1 – 434.6 MHz |
| Communication |
Two‑way, frequency hopping, AES128 encryption |
| Max Communication Distance |
Up to 1000 m (line-of-sight / open space) |
| Certifications / Standards |
CE, TÜV, EN 14604:2005+AC:2008 |
| Dimensions |
Ø 98 mm × 43.1 mm height |
| Weight |
140 g |
| Housing Material / Color |
ABS, white |
| Mounting |
Ceiling mount (surface mount) |
🛠 Warranty Information
Warranty terms typically depend on your distributor or local Dahua representative. Confirm warranty duration (often 1–2 years) and service details (repair vs replacement) with your supplier. Be sure to record the serial number and purchase date for any claims.
🏷 Brand (Dahua) Overview
Dahua Technology is a globally recognized leader in video surveillance, security, and IoT solutions. Their product portfolio spans video, alarm, access control, and integrated platform systems. Dahua emphasizes high reliability, interoperability, and consistent updates. Their AirShield wireless ecosystem (into which this smoke alarm integrates) supports remote control, alarm-video linkage, and cloud connectivity.
🧩 Practical Use Scenarios
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Residential homes / single‑family houses — ideal for rooms, hallways, or other indoor zones where wiring is difficult
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Apartments & condo units — wireless ease avoids disruptive installation
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Retail stores / small shops — to provide early smoke warning in sales or storage areas
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Rental properties / serviced villas — quick deployment and minimal maintenance
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Retrofitting older buildings without existing fire detection wiring
Pairing multiple units in a hub or zone allows broader coverage and centralized alarm propagation (if supported by the AirShield / hub system).
DATASHEET
🇦🇺 Excellence for the Australian and New Zealand Market
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This smoke alarm meets European EN 14604 standards and carries CE / TÜV certification, which is widely accepted in Australia/NZ (verify local code compliance).
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It is compatible with Dahua’s AirShield wireless security ecosystem, supporting smart linking with CCTV, alarm panels, and mobile apps.
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The product should be sourced from authorized Dahua distributors to ensure authenticity, warranty backing, and support.
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For Australian customers, ensure installation complies with AS 3786 (Smoke alarms, domestic).
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Warranty and service support should be confirmed locally with the Australian / NZ Dahua distributor to ensure prompt after-sales care.
❓ FAQs (with Product Code DHI‑HY‑SA21A‑W2)
Q: What is the power source of the DHI‑HY‑SA21A‑W2?
A: The DHI‑HY‑SA21A‑W2 is powered by a single 3 V CR123A lithium battery (replaceable), providing up to 3 years of standby life under normal conditions.
Q: What sound level (dB) does DHI‑HY‑SA21A‑W2 produce at 3 m?
A: The DHI‑HY‑SA21A‑W2 alarm produces an audible output of at least 85 dB(A) (and up to 90 dB) at 3 m.
Q: Does DHI‑HY‑SA21A‑W2 support wireless communication / linking?
A: Yes, the DHI‑HY‑SA21A‑W2 supports two‑way wireless communication with frequency hopping (433.1 – 434.6 MHz) and AES128 encryption.
Q: How many square meters can one DHI‑HY‑SA21A‑W2 cover?
A: For ceiling heights under 8 m, one unit of DHI‑HY‑SA21A‑W2 covers approximately 20 to 40 m².
Q: What certifications does DHI‑HY‑SA21A‑W2 carry?
A: The DHI‑HY‑SA21A‑W2 is TÜV and CE certified and complies with EN 14604:2005 + AC:2008.
Q: Is there a silence / hush feature in DHI‑HY‑SA21A‑W2?
A: Yes, the DHI‑HY‑SA21A‑W2 includes a built‑in silence function via its control button, which temporarily mutes the alarm for about 12 minutes.
Q: What is the operating temperature/humidity range for DHI‑HY‑SA21A‑W2?
A: The DHI‑HY‑SA21A‑W2 operates between –10 °C to +55 °C and can function in humidity levels up to 95% RH (non‑condensing).
