Odour extraction built into a concealed WC system can draw air from the pan and filter or discharge it according to the product design. It can improve the immediate toilet experience, but it is not a replacement for extracting humid air from the whole bathroom.
Two different problems
Odour extraction addresses air near the WC. Room ventilation addresses steam, condensation, mould and moisture from showers, baths and wet towels. A room can have one without adequately solving the other.
The system has parts to maintain
Filters, fans, power supplies and controls may need service. Confirm how the system is accessed through the flush plate or another approved route, and record the replacement parts.
Check the discharge route
The product may require a particular ventilation or electrical arrangement. Follow the manufacturer’s instructions rather than assuming that the concealed wall can simply vent into a cavity.
Combine the systems intelligently
Use source extraction for local odour where useful, and provide appropriate room ventilation to manage humidity. The two strategies can work together without being confused.
Read about concealed-cistern condensation in KZN, or see why extractor fans must discharge outdoors.