A room over the garage is cold; its supply register barely blows; the flex duct to it, visible in the garage attic, makes two kinked bends. The reporting link is:

This is a synthesis question with the evidence deliberately laid out in order: a symptom, a measurement and a visible cause. The room is cold, the register barely blows, and the duct feeding it is kinked. Flexible duct loses capacity dramatically when compressed or sharply bent — a kink can cut effective area by most of its cross-section, and unlike a concealed defect this one is visible in the garage attic and photographable. The value of the report is in linking the three: stating that the kinked duct is starving the room converts a vague comfort complaint into a specific, correctable defect with an obvious remedy. It also protects the client from being sold something larger, because the natural but wrong response to a cold room is to question the furnace.

The kinked flexible duct restricts airflow to that register, which explains both the weak delivery and the cold room. It is visible, specific and correctable, so the report links the symptom to the observed cause and recommends the duct be re-routed and supported.

Flexible duct must be pulled taut and supported at intervals to maintain its rated cross-section; kinks, compression and excessive length all reduce airflow substantially. Rooms over garages are additionally prone to heat loss through the floor assembly.

Symptom, Measurement, Cause — when a scenario hands you all three, your job is to connect them, not to introduce a fourth explanation.

Also note the floor assembly over the garage — insulation and air sealing there are a legitimate secondary finding, but the duct is the correctable defect the evidence points to.

• •Escalating a single-room complaint to a furnace replacement
• •Recommending supplemental heat instead of correcting the restriction
• •Substituting a generic envelope explanation for the observed cause