Air Vent Thrust

The indoor air was stagnant. I exited through the balcony gap, looking toward the open street below. An external HVAC exhaust unit hummed along the wall, venting a steady stream of warm, forced air upward through an angled aluminum louver. I stepped onto the metal grate directly above the exhaust slit. The upward thermal draft caught my stance instantly, pushing against the undercarriage of my boots. I crouched, lowering my center of mass and locking my ankles against the airflow to gauge its lifting threshold. A loose dry leaf fluttered upward in the jet, clearing the rail in seconds. The vertical thrust is consistent. An ideal kinetic launch point when I decide to leave the building.