Advanced Garage Ventilation Controller

CN-7232

The CN7232 is a stand-alone, smart controller designed for new or retrofit enclosed vehicle facilities that require fan ventilation because of the operation of combustion-based vehicles. The controller senses vehicle activity based on the measurement of carbon monoxide, nitrogen dioxide carbon dioxide or combustible gases. Based on concentrations measured throughout the garage the fans are modulated to ensure adequate air quality is always maintained. An easy to use keypad and display allow for easy user adjustment and check on system operating status.

The system’s control algorithms are designed to deliver maximize savings for operating energy (kWh) and peak energy (kW demand) particularly for fans using VFDs (Variable Speed Drives). As verified by utility in-field measurements, savings of up to 95% for operating and peak energy are possible by taking advantage of the fact that VFDs consume very little energy when fans can be operated at low speeds (e.g. at 25% speed a VFD uses about 2% of the energy needed when fans are at full power).

The CN7232 VFD strategy provides a low level of ventilation at all time to ensure there is always a reservoir of fresh air in the garage to handle an uptick in vehicle activity. Once levels exceed a base concentration of gases, the ventilation level is slowly increased based on garage gas concentrations. Users can also establish a number of control thresholds based on gas concentrations to ensure that fans do not go to full speed if there is a short-term rise in gas concentrations. This allows for maximum energy savings for system operation and reduction of kW demand.