ACI Duct Sensor Assembly
ACI Duct Sensor Assemblies: Precision Sensing for HVAC Systems
ACI (Automation Components, Inc.) has built its reputation on one core mission: delivering reliable, accurate building automation sensors for the HVAC industry. Within the Duct Sensor Assembly category, that expertise is especially evident. ACI's duct sensor assemblies are engineered to provide dependable air temperature measurement inside supply, return, and mixed-air ducts — a critical function in any commercial or industrial climate control system.
Thermistor and RTD Technologies in One Lineup
ACI's Duct Series Thermistor and RTD Sensors are designed specifically for HVAC system temperature control, and they come in thermistor and RTD sensor curves compatible with most Building Automation Systems (BAS) available today. This broad compatibility makes it straightforward to integrate an ACI duct sensor into an existing controls infrastructure without custom wiring or signal conversion.
The High Temperature Duct Series takes things further, offering a single-point duct sensor featuring a three-wire RTD sensor assembly and a 316 Series stainless steel probe — a construction choice that ensures both corrosion resistance and longevity in demanding airstream environments. Standard enclosure options for these assemblies include the "-GD" Galvanized or "-BB" Aluminum weatherproof enclosure , giving installers flexibility based on the installation environment.
Built for Accuracy and Durability
The standard duct mount configuration includes a mounting flange for quick installation and a foam pad to dampen vibrations, while the sensing element is double encapsulated to avoid sensor failures caused by moisture infiltration. This double-encapsulation approach is a hallmark of ACI's build philosophy across their temperature sensor range — most ACI temperature sensors are double encapsulated to ensure durability.
Three-wire sensors can be used with a two-wire transmitter, with the purpose of the third wire being to compensate for external lead wire resistance that would otherwise affect the accuracy of sensor output when used with a Building Management System or PLC. This design consideration matters in real-world installations where long cable runs are common.
Correct Installation for Maximum Performance
ACI duct sensors should be mounted close to the center of the duct and penetrate through any duct insulation at least 1 inch into the airflow, with probes sensitive within 1 inch of the tip, inserting through a 3/8-inch hole. Following these placement guidelines ensures accurate readings that reflect true airstream conditions rather than wall or insulation temperatures.
Applications and System Trust
ACI duct temperature sensors are designed for HVAC, Building Automation, and light industrial systems, with specific applications including zone control, air handling units, and temperature monitoring. ACI sensors come with a five-year warranty, demonstrating a commitment to product durability and long-term performance. For contractors and facilities managers who need sensors that work right out of the box and keep working, this warranty backing adds meaningful peace of mind.
Whether you're upgrading an aging BAS, commissioning a new air handling unit, or sourcing a drop-in replacement, ACI's duct sensor assemblies offer a well-proven, widely compatible solution. Explore the full ACI brand catalog or browse all Duct Sensor Assembly products to find the right fit for your application.