Meet the New DCV Requirements in ASHRAE 62.1 (Addendum ab) Ventilate properly to conserve energy and ensure a healthy indoor environment. Every space has unique ventilation rates and associated CO2 levels. DCV starts at the zone area ventilation rate and increases proportionally with CO2 levels. The system shall provide no less ventilation than required for the actual occupancy; providing more than the total design occupancy rate to the zone uses more energy. Measuring airfl ow is essential. Relying solely on CO2 levels to control the damper could result in an uncertain amount of air being brought in. EBTRON airfl ow measurement devices allow you to set upper and lower limits for ventilation, ensuring that it stays within the required range, saves energy, and maintains IAQ for healthy indoor environments.