Do I install a Chimney Balloon high in the chimney or low by the damper?

Checking doors for positive or negative air flow

Closed Round Center Pivot Butterfly Damper High Above the Fireplace.

Open Round Center Pivot Butterfly Damper High Above the Fireplace.

Measuring a Zero Clearance Heatelator Fireplace

Where to Measure a Heatelator Pre-Fab Fireplace