Can ASD fans be installed below ground in general?

ASD fans, or Active Soil Depressurization fans, are specifically designed to manage radon levels by drawing radon-laden air from beneath the foundation and expelling it outside. The installation of these fans below ground is generally discouraged due to potential issues related to moisture, accessibility for maintenance, and the risk of damage from environmental factors.

When considering the actual conditions under which ASD fans can be installed, specific exceptions apply, leading to the choice that states "No, with certain exceptions" being correct. These exceptions might include unique installation scenarios designed to mitigate other environmental risks or when employing additional protective measures that ensure the fan's functionality and longevity.

For instance, while the fan itself may not be suitable for below-ground installation in many standard situations, innovative engineering solutions may enable it to be deployed successfully under certain controlled conditions. Ensuring that the fan operates effectively and that it can be maintained is crucial for its performance in radon mitigation.

The other options do not fully grasp the complexity of the installation requirements and potential limitations of ASD fans in below-ground scenarios.