Related Clues:

• Blow off steam, two ways
• Ventilation tube
• Steam outlet
• ___ tape
• Blow off some hot air
• Hole in the wall
• Main, e.g.
• Unload stress
• Tear conduit
• Ductwork opening
• A/C opening
• What's totally tubular?
• Tubular channel
• Opening for gas or steam
• Heating system vent