This creates a powerful vacuum that violently sucks freezing cool air up from your basement or underground earth tubes, creating a constant, electricity-free breeze through the whole house. The HVAC lobby effectively banned this through modern "Energy Envelope" codes. By legally requiring homes to pass strict "Blower Door" air-tightness tests and mandating mechanical ventilation (HRVs), inspectors will fail any home that uses this brilliant open-air physics trick.