Messana Controls offers Demand-Controlled Ventilation (DCV) to operate ERV and HRV systems equipped with 0-10V fan speed regulation, through a feature called “Air Quality Adaptive Fan Speed Control”.
The speed of the ERV/HRV unit adjusts according to the detected eCO2 levels, which is a measure of indoor air quality. When eCO2 levels fall below the Low eCO2 setpoint, the unit operates at a Low speed. Conversely, when eCO2 levels exceed the High eCO2 setpoint, the unit operates at a High speed. For intermediate eCO2 levels, the unit linearly modulates the speed between the Low and High speeds.
Example
Let's say the following parameters are set via the user interface:
Low speed: 20%
High speed: 80%
Low eCO2 setpoint: 600 ppm
High eCO2 setpoint: 1,000 ppm
The system adjusts fan speed based on eCO2 levels for indoor air quality.
When eCO2 levels are below 600ppm, the unit operates at 20% of the fan's maximum capacity. If eCO2 levels exceed the 1,000ppm, the unit operates at a 80% of the fan's maximum capacity.
For eCO2 levels between the Low and High setpoints, the fan speed gradually adjusts in a linear manner to provide a proportional ventilation level (e.g., 35% for 700 ppm, 50% for 800 ppm, and 65% for 900 ppm). This ensures adequate ventilation, considering the highest eCO2 reading among all zones served by the unit.