How does occupant intervention affect ventilation efficiency in HRVs and ERVs?

Occupant intervention can decrease ventilation efficiency in Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs) primarily because it can disrupt the system's designed operation. When occupants manually adjust settings, close vents, or block airflow paths inappropriately, the balance and effectiveness of the ventilation process can be compromised.

HRVs and ERVs are engineered to work optimally based on specific airflow rates and conditions, taking into account factors like outdoor and indoor air temperature and humidity. If an occupant alters this balance in ways that go against the intended design—like limiting air exchanges or not utilizing features like timer settings—this can lead to less effective air exchange, reducing the system's ability to recover energy efficiently.

Therefore, the correct understanding of how occupant intervention affects these systems is that while initially, the intention may be to optimize comfort or airflow based on personal preference, it can unintentionally lead to a decline in the overall efficiency of the ventilation system.