What ventilation system is commonly used for pools?

The correct answer is based on the fact that a Heat Recovery Ventilator (HRV) is an effective ventilation system specifically designed for environments like pools, where maintaining a stable humidity level is crucial. Pools generate significant moisture, and HRVs work by recovering heat from the outgoing air that is being exhausted and using that energy to pre-condition the incoming outdoor air. This process not only helps in managing humidity but also enhances energy efficiency, which is particularly important in maintaining comfortable conditions around swimming pools.

In this context, while an Energy Recovery Ventilator (ERV) is also designed for ventilation and can recover both heat and moisture, HRVs are typically favored in pool environments because they do not transfer moisture into the pool area, thus preventing excess humidity that could lead to condensation and damage. The choice of HRV aligns well with the specific needs of pool ventilation, focusing primarily on heat transfer while keeping moisture levels balanced.

The other options like CFM refers to a measurement of airflow rather than a specific type of ventilation system, while Variable Refrigerant Flow (VRF) systems are primarily used for heating and cooling and may not directly cater to the specific environmental requirements found in pool settings.