What type of space is indirectly cooled and enclosed within the building's thermal envelope?

The correct answer is unconditioned space. This type of space refers to areas within a building that are not specifically heated or cooled by the HVAC system, yet they still have some degree of temperature regulation due to being enclosed within the building's thermal envelope.

Unconditioned spaces often include areas such as attics, crawl spaces, or basements that might see some heat exchange with the conditioned areas but are not actively controlled for temperature. They are affected by the internal environment of the building, meaning they can warm up due to heat from the conditioned spaces or cool down relatively quickly if the HVAC system is not running.

In contrast, conditioned spaces are actively cooled or heated to maintain comfort levels for inhabitants, while heated spaces are those that are maintained at specific temperatures intentionally. Supplemented spaces might refer to areas where additional heating or cooling is provided but don’t typically denote the indirect cooling aspect that unconditioned spaces are recognized for.