When inspecting air conditioning systems, which of the following is NOT permitted?

Operating an air conditioning system when the exterior temperature is below 65 degrees Fahrenheit is not permitted due to the risk of damaging the system. When the temperature is too low, the refrigerant can fail to function properly, potentially leading to compressor damage and other issues within the unit. This practice is generally considered unwise and might violate manufacturers' guidelines for safe operation.

In contrast, reporting on electronic air filters, opening panels for homeowner maintenance, and activating systems that have been shut down (assuming they are safe to operate) fall within the typical scope of a home inspection. These actions can provide valuable insights into the system's condition and maintenance requirements, ensuring that potential issues are identified and communicated to the homeowner.