Know Exactly What Your HVAC System Is Delivering
Direct in-duct visibility for better air, smarter ventilation, and more efficient HVAC operation.
ThinkLite In-Duct Flair measures incoming air inside the HVAC duct before it reaches occupied spaces. With clearer visibility into real conditions, operators can identify air quality issues earlier, optimize ventilation more intelligently, and reduce unnecessary energy use across the building.
Save Energy by Ventilating Smarter
Reduce unnecessary conditioning and support more efficient HVAC operation.
Ventilation strategy plays a major role in HVAC energy performance. The ThinkLite In-Duct Flair helps teams operate more efficiently as outside air conditions change, supporting smarter air management, lower unnecessary conditioning, and stronger day-to-day HVAC performance.
Learn more: Review the DOE guidance on ventilation and energy use.
Why monitor air quality inside the duct?
See where air quality issues begin, not just where they appear.
Air quality problems do not always start in the occupied space. Some are linked to outside air, some to filtration, and some to the HVAC system itself. Monitoring inside the duct adds the system-level context needed to trace changes and troubleshoot with greater confidence.
Trace issues to the source
Separate outside air, filtration, and HVAC-related changes when conditions shift.
Catch system changes earlier
Spot airflow, filter, and duct-side changes earlier for faster investigation.
Support faster troubleshooting
Give operators better context for maintenance, investigation, and daily HVAC decisions.
Turn in-duct data into better building decisions
Ductwork is a demanding sensing environment. Airflow, pressure, and turbulence can vary across systems, which can affect readings when a device is not designed specifically for in-duct use.
Strengthen reporting and documentation
Improve communication with tenants and stakeholders
Reduce blind spots in hard-to-access areas
Optimize ventilation more effectively
Make better-informed energy decisions
Engineered for in-duct air quality monitoring
ThinkLite In-Duct Flair uses a protected sampling approach that brings duct air into a dedicated sensing chamber inside the enclosure. This helps support more stable measurement while protecting core electronics from direct exposure to harsh duct conditions.
True in-duct monitoring depends on more than mounting location alone. It also depends on how air is sampled, how the sensing chamber is protected, and how the system is designed for service in real HVAC environments.
How ThinkLite In-Duct Flair works
ThinkLite In-Duct Flair mounts directly to ductwork and uses two external sampling tubes to guide air through a protected sensing chamber. This supports more controlled measurement inside the HVAC system.
Measured data is then made available through dashboards and supported building-system integrations, so operators can monitor conditions, review trends, and act faster when changes occur.
Step 1
Air enters through the inlet tube.
Step 2
The sample passes through a protected sensing chamber.
Step 3
Key air quality metrics are measured in real time.
Step 4
Data is delivered to dashboards and supported BAS/BMS integrations.
Measure the conditions that define duct air quality
From particles and gases to temperature, humidity, and pressure, ThinkLite In-Duct Flair captures the conditions that define air quality inside the duct.
Particulate Matter (PM10–PM0.1) is a range of airborne particles categorized by size, from inhalable coarse dust (PM10) and fine combustion soot (PM2.5) down to ultrafine particles (PM0.1). Because these categories are nested, smaller particles like PM0.1 are the most hazardous as they can bypass the lungs and enter the bloodstream directly.
A high-resolution count of individual solid and liquid particles suspended in the air. This metric tracks everything from large allergens to microscopic particles small enough to enter the bloodstream.
Total Volatile Organic Compounds (TVOCs) are airborne chemicals from sources like paints, cleaning products, perfumes, and mold. Measured in parts per billion (ppb), high levels can cause irritation, fatigue, nausea, and even damage to organs or the nervous system. Some VOCs are toxic and known carcinogens.
CO₂ is a colorless, odorless gas from people and combustion. It’s used to estimate occupancy and ventilation. Elevated levels can affect cognition and increase disease transmission risk. OSHA flags it as a safety concern above 5,000 ppm. Indoors, it’s typically kept within 600 ppm of outdoor air, which averages 400–450 ppm.
SO₂ is a harmful gas released from burning fossil fuels. It’s commonly monitored outdoors due to its impact on air quality and health, especially in areas near traffic or industry. Indoors, it can enter through ventilation or come from sources like gas appliances. Monitoring SO₂ helps protect people and equipment, especially in sensitive environments like data centers where it can cause corrosion and hardware damage.
NO₂ can cause damage to the human respiratory tract and increase a person’s vulnerability to, and the severity of, respiratory infections and asthma
CO, breathing air with a high concentration of CO reduces the amount of oxygen that can be transported in the bloodstream to critical organs like the heart and brain.
O3, unsafe ozone level from pollution and consumer products cause harmful health effects and damage the lungs.
NH₃ is a pungent gas released from sources such as agriculture, cleaning agents, refrigeration systems, and certain industrial processes. Indoors, it can come from cleaning products, building materials, or infiltration from nearby outdoor sources. High concentrations can irritate the eyes, skin, and respiratory system, and prolonged exposure can be harmful. In sensitive environments like laboratories or data centers, ammonia can also cause corrosion and damage to equipment, making continuous monitoring important for both health and asset protection.
The CDC and ASHRAE recommend that indoor temperatures range from 68.5°F to 75°F in the winter and 75°F to 80.5°F in the summer. Higher temperatures can speed up chemical reactions and increase emissions of volatile organic compounds (VOCs).
RH: is an important factor for maintaining good indoor air quality (IAQ). The ideal RH level for IAQ is generally considered to be between 35% and 60%.
The force exerted by an air column above a surface as gravity pulls it down is known as air pressure. Simply put, this is the force of air pressing against something when it is in contact with it. Air pressure affects the sustainability of the building, our energy consumption, and indoor air quality that directly impacts human health.
Built for real mechanical environments
ThinkLite In-Duct Flair uses a rugged enclosure built for demanding HVAC installations. It is well suited for mechanical spaces, utility areas, and other environments where durability, service access, and protected sensing matter.
CSA Certified
UL Listed
IEC 60529 IP68
UL 94 5VA flammability rating
NEMA/EEMAC 6P, 4X
UV-resistant
Dual-tube sampling architecture
Direct duct mounting
Front access for inspection and service
Protected cable routing
Visible internal status confirmation
On site replaceable modular sensors
Integration, Connectivity, and Power Options
ThinkLite In-Duct Flair is designed to fit into modern building systems with flexible integration, communication, and power options. This makes deployment easier across a wide range of project requirements.
BACnet MS/TP & IP
Modbus RS-485
Modbus IP
MQTTs (Local & Cloud)
Open API (Local & Cloud)
Ethernet
Wi-Fi
4G LTE
Serial Communication
LoRaWAN®
PoE (Power over Ethernet)
10-30V DC Direct Wire
24V AC Direct Wire
110-240V AC via USB-C
Low-Voltage Power
Common questions
An in-duct air quality monitor measures air directly inside HVAC ductwork so teams can understand delivered air quality and system-side conditions before air reaches occupied spaces.
Room monitors show what occupants are experiencing. In-duct monitors show what the HVAC system is delivering. Used together, they provide a more complete picture of building air quality.
Common installation points include supply ducts and return ducts, depending on whether the goal is to verify delivered air quality, investigate changes across occupied areas, or support HVAC troubleshooting.
Depending on model configuration, the system can monitor particles, CO₂, TVOCs, selected gases, temperature, and relative humidity.
Yes. Supported integration options can include BACnet, Modbus, MQTT, API, and cloud-connected workflows.
The enclosure platform is designed for demanding service conditions and strong environmental protection.
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