Air conditioning affects balloons in three separate ways, and only one of them is permanent. The first is physics: gas contracts as it cools, so a balloon sitting in a cold stream visibly shrinks and loses lift, then recovers its size once it warms back up. A sagging balloon under an air conditioning vent is usually not faulty at all.
The second effect is mechanical and does real damage. A steady draft pushes balloons across the room and holds them against walls, ceiling texture and hot spotlights, where the surface abrades until it bursts. In a room with strong airflow this is the most common reason a ceiling set thins out during an evening.
The third is drying. Constantly circulating dry air ages latex faster, so it goes matte and brittle sooner than it would in a stable room. None of this makes air conditioning the enemy, since a cool stable room is still the best environment for balloons overall, but the set should be placed away from the vents rather than under them.
- Cold contracts the gas: balloons shrink, then recover when warmed
- Draft pushes balloons into walls, textured ceilings and spotlights
- Dry circulating air ages latex faster and dulls the finish
- Place clusters and bouquets away from vents and open windows
- Weight bouquets properly so the airflow cannot move them around