Freon Leak Sensor (Freon Leak Detector) — Fixed Monitoring for HVAC/R
Winsen® manufactures electronic leak sensors for legacy “Freon” refrigerants (e.g., R22, R12) and modern A1/A2L/A3 gases (R134a, R410A, R32, R454B, R1234yf/ze, R290, R600a). Choose NDIR for ppm early warning and MOS/NDIR for %LEL safety interlocks. Standard 4–20 mA, RS-485 Modbus, and relay outputs make BMS/PLC integration simple.
What “Freon” Means in Practice
Outside North America, people often say “Freon” to mean any refrigerant. Technically, Freon™ is a trademark historically used for CFC/HCFC/HFC products such as R12 and R22. This page uses “Freon leak sensor” in the common, generic sense: electronic fixed sensors that detect refrigerant leaks in HVAC/R spaces.
NDIR Refrigerant Sensor
Semiconductor Refrigerant Sensor
Model Guide — Select by Gas Family
A1 “Freon” & HFC/HFO — NDIR PPM
- Typical ranges: 0–1,000 / 0–5,000 ppm
- Outputs: 4–20 mA, RS-485 Modbus, 1–2 relays
- T90: ≤ 30 s • Low drift, long life
*R22/R12 are legacy service gases in many regions.
A2L Low-GWP — NDIR PPM or %LEL
- PPM early warning (NDIR) and/or 0–100% LFL/LEL
- 4–20 mA / RS-485 / relays
- Ideal for VRF rooms & heat pumps
A3 Flammable — %LEL Safety
- Range: 0–100% LEL (NDIR-LEL or MOS)
- Relays for ventilation & shutdown interlocks
- Housings up to IP65 for rough areas
Technology Comparison
| Technology | Best For | Range | Advantages | Considerations |
|---|---|---|---|---|
| NDIR | A1 ppm; A2L ppm/%LEL | ppm → %LEL | High selectivity & stability; low drift; long life | Protect from heavy condensation/dust (filters/enclosures) |
| MOS | A2L/A3 %LEL | 0–100% LEL | Fast response; robust; cost-effective | Some cross-sensitivities; periodic calibration recommended |
| Catalytic Bead | General hydrocarbons | 0–100% LEL | Well-proven for flammables | Needs O₂; can be poisoned by silicones/lead |
Placement & Setpoints — Good Practice
- Mounting height: Most “Freon”-class and modern refrigerants are heavier than air → mount low; confirm with on-site airflow.
- Coverage: ~5–10 m radius per sensor in open rooms; add units near valves/joints and low pockets.
- Alarms: A2L/A3: pre-alarm ≈25% LFL; main ≈50% LFL. A1: ppm bands (e.g., 1,000–5,000 ppm) per project spec.
- Interlocks: Pre-alarm → ventilation; Main → equipment shutdown + beacons/BMS alarm.
Typical Applications
VRF/VRV indoor units & hotel rooms
Mount low (~150–300 mm AFF) near indoor units and pooling points; link alarms to fan shutdown and fresh-air purge.
Chiller & machinery rooms, compressor racks
Place around compressors, oil separators, valves, and low spots/sumps; IP-rated housings recommended.
Cold storage & refrigerated display cases
Install beneath cases and along manifolds; choose condensation-resistant designs and night-curtain interlocks.
Data center in-row/CRAC units
Put in return air, under raised floors, near coils; ppm early warning protects uptime, with BMS ventilation override.
Heat pump & general HVAC equipment
For A2L/A3, use %LFL setpoints for safe shutdown; weatherproof housings for outdoor units.
Core Specifications
| Parameter | Value / Option |
|---|---|
| Power | 12–24 VDC (others on request) |
| Outputs | 4–20 mA (2/3-wire), RS-485 Modbus RTU, 1–2 relays (N.O./N.C.) |
| Measurement | NDIR ppm and/or %LFL (MOS/NDIR-LEL) |
| Response Time (T90) | ≤ 20–30 s typical |
| Operating Conditions | −20…+50 °C; 15–95% RH non-condensing (model-dependent) |
| Enclosures | Wall, panel, duct; housings up to IP65 |
| Compliance | CE & RoHS; designed for BMS/PLC integration |
Sensor Technologies: NDIR vs. MOS
| Feature | NDIR (Infrared) | MOS (Semiconductor) |
|---|---|---|
| Accuracy | High (±2% FS) | Moderate (±5% FS) |
| Response Time | 1–3 seconds | <1 second |
| Power Consumption | <25 mW | <50 mW |
| Lifetime | >5 years | 2–3 years |
| Cost | Higher | Lower |
| Best Use | Safety-critical HVAC & commercial | Low-cost appliances |
For large-scale and safety-critical systems like district cooling, hotels, and cold storage, choose NDIR technology. For home appliances and low-cost products, MOS sensors provide a cost-effective alternative.
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.
Humiling ng Konsultasyon
FAQs — Refrigerant Leak Sensors & Detectors
Is a Freon leak sensor the same as a refrigerant leak sensor?
In everyday use, yes. “Freon” is often used generically for refrigerants. Our fixed electronic sensors detect the specified gas family regardless of branding.
Do I need ppm or %LEL measurement?
Use ppm (NDIR) for early warning and process/comfort monitoring; use %LEL (MOS/NDIR-LEL) to drive safety interlocks for A2L/A3 gases. Many facilities deploy both tiers.
Where should sensors be installed?
Near likely leak sources (compressors, valves, joints) and low-lying accumulation points. Avoid strong supply air that could bypass the sensor.
How often is calibration required?
12–24 months is common, with periodic bump tests depending on environment and criticality.
Can Winsen customize for OEM programs?
Yes—ranges, firmware, connectors, enclosures, and branding can be customized for volume deployments.
