AC Freon Leak Sensor (Leak Detector) — Split/VRF • Central AC • Auto A/C
Winsen® manufactures electronic leak sensors for air-conditioning refrigerants across residential, commercial, and automotive applications. For building HVAC, we cover R410A, R32, R454B, and legacy R134a/R22*; for automotive A/C we support R1234yf and R134a. Choose NDIR for ppm early warning and MOS/NDIR for %LEL safety interlocks with 4–20 mA, RS-485 Modbus, and relay outputs ready for BMS/PLC integration.
Model Guide — Pick by AC Type & Refrigerant
Home/Commercial AC — A1 (NDIR PPM)
- Ranges: 0–1,000 / 0–5,000 ppm (custom)
- Outputs: 4–20 mA, RS-485 Modbus, 1–2 relays
- T90 ≤ 30 s • Low drift, long life
*R22 is legacy/service gas in many regions.
Home/Commercial AC — A2L (NDIR PPM / %LEL)
- PPM early warning (NDIR) and/or 0–100% LFL/LEL
- 4–20 mA / RS-485 / relays
- Ideal for VRF/VRV rooms & hotel guestrooms
Automotive A/C — A2L/A1
- NDIR ppm for process/comfort; %LEL for interlocks
- Integrate at charge stations, test booths, bays
- Modbus for line interlocks & traceability
What “AC Freon” Means
In everyday language, “Freon” often means any AC refrigerant. Technically, Freon™ is a trademark historically used for CFC/HCFC/HFC products (e.g., R12/R22). This page uses “AC Freon leak sensor” in the common sense—electronic fixed sensors that detect refrigerant leaks in air-conditioning systems.
NDIR Refrigerant Sensor
Semiconductor Refrigerant Sensor
How Infrared (NDIR) Refrigerant Sensors Work
| Stage | What Happens | Benefit |
|---|---|---|
| Emission | IR source emits broadband light through the gas sample. | Reliable optical excitation |
| Filtering | Narrowband optical filter targets refrigerant absorption bands; a second channel serves as reference. | Gas selectivity & drift compensation |
| Detection | Photodetectors measure attenuated signal vs. reference; MCU computes concentration. | Stable ppm / %LEL output |
| Compensation | Temperature/pressure & baseline routines (e.g., ABC optional) correct drift. | Long intervals between calibrations |
Typical AC Applications
Split/VRF indoor units & hotel rooms
Mount low (~150–300 mm above floor) near indoor units, under beds/sofas in hotel rooms, and other pooling points. Pre-alarm → fresh-air purge; main alarm → fan/indoor-unit shutdown.
Central AC air handlers & mechanical rooms
Place near coils, expansion valves, and floor low spots/sumps; use IP-rated enclosures. Integrate with BMS to start purge fans at pre-alarm and trip systems at main alarm.
Line sets, evaporator/condensing sections
Monitor around brazed joints, service valves, and manifolds; avoid strong supply streams that bypass the sensor.
Automotive service bays & EOL test
Position near charging/recovery stations and low-lying areas. Use ppm early warning plus %LFL safety interlocks (beacon/horn/vent).
Technology Options
| Technology | Best For | Range | Advantages | Considerations |
|---|---|---|---|---|
| NDIR (Infrared) | A1 ppm; A2L ppm/%LEL | ppm → %LEL | High selectivity & stability; not O₂-dependent; long life | Protect from heavy condensation/dust (filters/enclosure) |
| MOS (Semiconductor) | A2L/A3 %LEL | 0–100% LEL | Fast response; robust; cost-effective | Cross-sensitivities possible; periodic calibration advised |
| Catalytic Bead | General hydrocarbons (A3) | 0–100% LEL | Mature tech for flammables | Requires O₂; susceptible to poisons (silicones/lead) |
Placement & Setpoints — Good Practice for AC
- Mounting height: Most AC refrigerants are heavier than air ⇒ mount low; confirm with room airflow.
- Coverage: ~5–10 m radius per sensor in open rooms; add units near valves/joints and low pockets.
- Alarm tiers: A2L/A3: pre-alarm ≈25% LFL; main ≈50% LFL. A1: ppm tiers (e.g., 1,000–5,000 ppm) per design spec.
- Interlocks: Pre-alarm → ventilation/start purge; Main → equipment shutdown + horn/beacon/BMS notification.
Finalize thresholds and quantities against local codes and your project specification.
Why Global Clients Choose Us?
The company consistently adheres to the quality policy of “Fine Craftsmanship, Scientific Innovation, Pursuit of Excellence, and Value-Added Service.” By formulating production process control plans and work instructions, it has established a standardized, accountable, and regulated process management system. Additionally, the company has independently developed an MES production management system, enabling comprehensive and visual management across the entire workflow.
30+ YEARS OF EXPERIENCE
R&D, manufacture and sales of sensors and sensing solutions.
QUALITY GUARANTEE CONTINOUS IMPROVEMENT
Complete and rigid process flow control, coupled with significant improvements.
INTERNATIONAL MARKET
Deliver sensing products to more than 100 countries and regions.
STABLE SUPPLY CHAIN RELIABLE PRODUCTION
Core components not subject to constraints, advanced equipments for manufaturing and test.
R&D STRENGTH TECHNOLOGY INNOVATION
200+ patents, 180+ R&D team members, self-built labs for continous innovation.
ONE-STOP SERVICE
Professional consultation, fast delivery, 24 hours after-sales support.
Leading the Industry, Innovative & Controllable Technology
With robust R&D capabilities, we maintain sustained input in R&D and unwavering commitment to technological innovation. This not only ensures that we remain at the forefront of industry but also drives continuous innovation, leading the future trend of the sensing industry.
FAQs — Infrared (NDIR) Refrigerant Leak Sensors
Is “AC Freon” the same as refrigerant?
In common use, yes. Freon™ is a trademark historically used for certain refrigerants; we use the term generically here to match search intent.
Do I need ppm or %LEL measurement for AC?
Use ppm (NDIR) for early warning and comfort/process protection. Use %LEL (MOS/NDIR-LEL) to drive safety interlocks for A2L/A3 gases (e.g., R32/R454B).
Where should sensors be installed in rooms?
Near indoor units, valves, joints, and floor-level accumulation points; avoid strong supply air. In hotels, place low and accessible for maintenance.
How often is calibration required?
12–24 months is typical with periodic bump tests; harsher environments may need more frequent checks.
Can Winsen customize for OEM rollouts?
Yes—ranges, firmware, connectors, harnesses, housings, and branding are customizable for volume programs.
