The “Olfactory” Core of Smart Fresh Air Systems: Complete Analysis of Nexisense Gas Detection Technology

In modern buildings and industrial environments, fresh air systems are no longer merely “exhaust fans” but are intelligent air processing hubs integrating filtration, disinfection, sterilization, oxygen enrichment, and preheating. As attention to indoor air quality (IAQ) grows, the ability to sense gas composition in real-time and accurately has become a key indicator of system intelligence and safety. Nexisense, an industry-leading gas detection expert, has designed a complete gas monitoring solution for fresh air systems, helping create safe and smart breathing environments.

Structure of Modern Fresh Air Systems and Necessity of Monitoring

Fresh air systems are essentially independent air circulation units, composed of supply and exhaust subsystems. Depending on building structures, they are typically ducted or ductless. Their operation involves supplying treated “fresh air” into an enclosed space while simultaneously exhausting stale air, creating a controlled “fresh air flow field.”

However, air movement alone does not ensure healthy air quality. Efficient fresh air systems perform filtration, sterilization, and even oxygen enrichment. For example, in medical or high-end offices, ozone may be introduced for disinfection, or oxygen concentrators increase oxygen content. Without precise monitoring, excessive ozone or insufficient oxygen can compromise safety and air quality. Installing professional gas detectors at inlets, outlets, and ducts is the basis for closed-loop system control.

Full-Scenario Gas Monitoring Deployment by Nexisense

Nexisense provides targeted hardware deployment schemes depending on monitoring locations. Due to environmental complexity, a single monitoring method cannot fit all. Inlets, outlets, and enclosed ducts have distinct physical sampling requirements.

Sensitive Detection at Inlets and Outlets: Diffusion Monitoring

At air exchange points, such as inlets and outlets, airflow is relatively stable and space is open. Nexisense recommends diffusion-type online gas concentration detectors, which use natural molecular diffusion to reflect actual human breathing gas levels and detect external pollution intrusion in real-time.

Accurate Sampling Inside Ducts: Duct Monitoring

Inside ducts, high air pressure and flow speed make diffusion devices unreliable. Nexisense duct gas detectors, installed via flanges, threaded connections, or bypass sampling modules, use fluid mechanics-optimized internal structures to stably extract samples from high-speed airflow, ensuring effective filtration and disinfection.

Core Technology: Nexisense Online Detection Series

• High-performance sensing chips and deep optimization: Using imported high-performance sensors with secondary calibration and temperature compensation algorithms, maintaining linearity and repeatability under varying conditions.

• Plug-and-play, high-efficiency integration: Supports 24V standard power, outputs real-time gas concentration immediately after power-on.

• Flexible multi-parameter customization: Wide range options including:

• Oxygen (0-30% VOL): Prevents hypoxia in enclosed spaces.

• Carbon monoxide (0-1000 PPM): For underground parking fresh air linkage.

• Hydrogen sulfide (0-50 PPM): For industrial or sewage ventilation monitoring.

• Ozone (0-1/5/10 PPM): Monitors disinfection residue for respiratory safety.

Intelligent Linkage: Closed-Loop Management from Monitoring to Control

Single concentration display is only the first step. Nexisense solutions offer system integration and linkage:

• Unified power and centralized display: Provides stable power to probes, displays real-time readings at control rooms.

• Logical linkage control: Low/high alarm points trigger relay outputs to start fans, open valves, or shut down devices.

• Signal conversion: Converts sensor signals to 4-20mA analog, RS485 digital (Modbus RTU), or wireless signals for building automation systems (BAS) integration.

Industrial and Civil Applications

Nexisense technology applies to residential, industrial, laboratories, and public facilities. In chemical plants or precision labs, detecting hazardous gases is critical. Integrated CO2 and PM2.5 sensors allow occupancy-based ventilation, reducing energy consumption while maintaining air freshness.

Communication Protocols and Compatibility

Nexisense devices are optimized for global integration, compatible with analog and industrial IoT platforms. They can operate independently or as key nodes in smart home or smart factory ecosystems, providing continuous and stable data streams.

Frequently Asked Questions (FAQ)

Q1: Why install detectors at both inlet and outlet?
A: Inlet detection monitors outdoor pollutants entering, outlet detection reflects indoor pollutant removal efficiency. Dual monitoring evaluates system performance accurately.

Q2: Installation difference between duct-type and diffusion detectors?
A: Diffusion is wall-mounted and uses natural airflow; duct-type requires pipe penetration with sealed components for high-speed airflow sampling.

Q3: Recommended calibration frequency?
A: Every 6-12 months for accurate long-term operation; Nexisense supports easy calibration, reducing maintenance costs.

Q4: Can the detector directly start the fan if gas exceeds threshold?
A: Yes, built-in relay outputs provide switch signals to fan contactors for automatic control.

Q5: Role of ozone detection in fresh air systems?
A: Ozone disinfects, but high concentration is harmful. High-precision sensors ensure safe disinfection levels.

Q6: Performance in high humidity?
A: Humidity compensation design ensures stable operation in 0-95% RH; optional pre-treatment for extremely high humidity.

Q7: Remote monitoring via mobile app?
A: Yes, IoT solution uploads data to cloud for real-time monitoring, alarm notifications, and historical review.

Q8: Oxygen sensor lifespan?
A: Electrochemical oxygen sensors last 2-3 years; modular design allows easy core replacement.

Conclusion

Fresh air systems are the “lungs” of buildings, directly impacting occupant safety and quality of life. Nexisense provides reliable “digital senses” through professional online gas monitoring. From high-precision sensors to intelligent controllers, the solution enhances detection professionalism and integration flexibility, advancing the industry from “mechanical ventilation” to “smart breathing.” Nexisense is the ideal partner for safe and intelligent ventilation environments.