Product Overview
Unused ACI Automation Components A/DIFF-ENT Differential Enthalpy Controller – Open Box
The ACI A/DIFF-ENT differential enthalpy control module compares outdoor and return air enthalpy to manage economizer operation in HVAC systems. Designed for commercial and industrial ventilation control, it helps optimize energy efficiency by determining when outside air can be used for cooling.
Automation Components Inc. (ACI) is a U.S.-based manufacturer known for HVAC and building automation sensors and controls. Their designs emphasize reliability and field serviceability, and the A/DIFF-ENT controller is no exception—built for accurate measurement of both humidity and temperature to calculate total heat content (enthalpy) for intelligent economizer decisions.
Product Condition
Unused, open box. The instruction sheet is missing. There is no selector switch on this unit, which differs from certain model variants. The module shows no signs of prior installation or use.
Product Overview
The A/DIFF-ENT controller monitors differential enthalpy between outdoor and return air sensors to control dampers or economizer systems. It uses inputs from compatible ACI humidity and temperature sensors to trigger economizer engagement when outdoor conditions are suitable. Compact and designed for control panel integration, the unit interfaces easily with existing HVAC control architectures.
Key Features
- Model: A/DIFF-ENT Differential Enthalpy Control
- Manufacturer: Automation Components Inc. (ACI)
- Determines enthalpy difference between outdoor and return air
- Controls economizer dampers for energy-efficient cooling
- Compatible with ACI temperature and humidity sensors
- Panel-mount design for building control systems
- Open-box unit, unused and uninstalled
- No selector switch (variant-specific configuration)
- Missing printed instruction sheet
- Built by ACI – known for reliable HVAC control components
Applications
- Commercial HVAC economizer systems
- Building automation control panels
- Energy management and ventilation control
- Air handling and rooftop unit integration
- System replacements or retrofit installations
- HVAC testing and configuration training
- Controls engineering or component inventory
Frequently Asked Questions
Is this controller new?
It is unused and classified as open-box. The packaging was opened, but the unit shows no signs of prior installation.
Is there a selector switch?
No. This specific model does not include a selector switch, which may appear on other A/DIFF-ENT variants.
Are installation instructions included?
No printed manual is included, but documentation is available from ACI’s technical support or website.
What does this controller do?
It compares outdoor and return air enthalpy to determine whether outside air can be used for free cooling, optimizing energy efficiency.
Can it be used with any sensor?
It is designed for use with ACI humidity and temperature sensors calibrated for differential enthalpy control.
Engineered for precision HVAC control, this ACI differential enthalpy module remains uninstalled yet ready to guide systems toward smarter, more efficient air handling.
